Jays a-JAYS Four iPhone - Reviews
Pros: Great ipod/iphone controls, great ergonomic design, nice thick tangle free cable, plenty of earbud sizes to choose from.
Cons: Poor isolation, buds tend to pop out, audio is a tad "hollow" at times, no pouch!
I bought these as a replacement for the crap apple headphones.  I immediately appreciated the nice, loud and solid sound, and how they felt like they belonged in my ears.   The concave shape of the casing just feels right.  The nice tangle free cable was great for just tossing in my pocket and pulling them out, giving them a shake or two, and they are good to go.  Another design feature I liked was the 90 degree 1/8 jack.  It was all but totally flat, letting the audio source be even more comfortable in your pocket.   The inline controls are top of the line as well.  nice round buttons, with a satisyfying tactile feel, easy to find with one hand, and  easy to navigate the controls.   These are still the nicest controls I have experienced to date.  These were very rugged as well,  besides the paint eventually chipping off of the in-line controls. It also took me a bit of trial and error to find buds that fit me well without popping out, but I eventually found suitable ones.  I did find that during any type of sweating, these were a chore to keep in.   These also did not come with a pouch, though I found that I didnt really need it most of the time,  I would just shove them in my bag and go.  They do come in a nice plastic case, with all of the earbuds, but this is too bulky to carry around.  
Overall totally worth the price as a very suitable upgrade from cheapo apple sets,  I find them MUCH more superior to the Klipsch and Beats  ipod/iphone sets you see everywhere...  the audio however is tuned more for voice calls, which can leave some of your favorite songs sounding a bit empty.  Still a very very decent set of voice call capable earbuds. 
"...I find them MUCH more superior to the Klipsch and Beats ipod/iphone sets you see everywhere..."
This is just too obvious. I don't mean to be rude, but did you have to add it to your review? Well, regarding Klipsch, I'm unsure about that, as the Image S4 sounds really nice.
Pros: Look simply superb, sumptuous rich sound with Dirac in use.
Cons: It’s a big price jump for a mic and its essentially an Idevice only earphone.
t-JAYS Four Review and JAYS Curves Quick Review
Full review at http://www.head-fi.org/t/659123/t-jays-four-review-and-jays-curves-review
Thanks to JAYS for the sample.
Brief:  Uber fancy EQ stuff for Idevices
Price:  £80 for the t-JAYS Four £2 for JAYS Curves
Specification:  Driver Type 10 mm TCD Dynamic Speaker, Sensitivity 98dB @ 1kHz, Impedance 16 Ohm @ 1kHz, Frequency Response 15 Hz – 25 000 Hz, Earphones Finish  Rubber Coated Black / Metal, Isolation  -40dB @ 2kHz, Size (L)17.5 x (W)6.9 x (H)14.8 mm, Weight 10 grams (0.35 oz), Cord Type          Dividable TPE coated & Kevlar reinforced cables Length        60 cm (23.5 in) + 70 cm (27.5 in), Plug Straight, Silver-Plated Stereo Plug 3.5mm (1/8 in)
Accessories:  5 pairs of tips, a shirt clip and a rather cool case.
Build Quality:  The t-JAYS ooze sumptuousness.  They are an image of perfection and feel just as well constructed in the hand.
Isolation:  A bit so so.  Fine for a dynamic and no doubt perfectly adequate for normal situations.  Not something for a daily Tube commute though or a long flight.  With music going though enough to block out traffic noise so do look out, or you’ll get yourself run over.
Comfort/Fit:  excellent.  Worn up or down they were effortless and perfectly comfortable, even all day.  One caveat, worn down the mic did catch on my collar which annoyed me, up it did not.
Aesthetics:  One of the best looking IEM’s, period.
Sound:  Sans Dirac they are really, really bass heavy and I can’t say I liked them much.  Not for £80 anyway, I don’t care how nice they look!  Slap an extra £2 and you get the Dirac stuff which you can think of as a super fancy EQ setting.  It makes a huge difference and has clearly been aimed at compensating for the shortcomings of Idevices as it is improving the t-JAYS.  The Ipad 2 I used could make these sound good where it frankly struggled with comparably priced IEM’s.  Adding and amp of course solves the issue but I get people using an Iphone as a DAP aren’t going to do that.  The dirac stuff makes the t-JAYS sound into a smooth, lush sounding IEM.  Bass is still big and thick but not suffocating.  The mids are thickish and liquid but can actually flow, smoothly and I dare a say beautifully.  The highs are a bit soft and genteel to continue a warm theme but offer up a nice level of detail, shimmer and accuracy.  They are detailed but kind to the ear.  Smooth and warm with a hint of something else, sharp and tart, like a microwaved big slice of a Black Forrest gateau.
Value:  £80 for the t-JAYS Four is a bit steep when the Three is only £40, £40 is a lot to ask for a mic.  The £2 for the Jays Curves programme is however a no brainer.  If you’re an Idevice user and if you have a pair of t-JAYS (or also a-JAYS imo) then it’s the best audio upgrade you’ll ever see for £2. 
Pro’s:   Look simply superb, sumptuous rich sound with Dirac in use.
Con’s:  It’s a big price jump for a mic and its essentially an Idevice only earphone.

Pros: Tangle-free cable, packaging, good microphone, good build quality, decent mids and treble
Cons: Difficult fit, cable noise, little isolation, anemic sound
I bought these after my pair of Sennheiser CX-300 II's fell out of my pocket, as a short-term solution until I could find something I really wanted.   The packaging on them is excellent, with the headphones in a sturdy box that you're unlikely to ever lose.  Included with the headphones are five different pairs of tips, for different sized ears, a lengthy printed user manual, and the headphones themselves.
The headphones themselves are very sturdily built,  and have a flat, completely tangle-free cable and an iPhone mic.  The tangle-free aspect of them is very enjoyable, as you can put them anywhere, and you're not going to have to spend five minutes untangling some gordian knot in order to use them.  Also, while the headphone is built entirely in plastic, they seem to be able to take a good beating.  Also, the headphone jack is excellent - it's angled and very low profile, and so is very good for those who put their phone or player in their pocket.
As for wearing comfort, the a-jay four are very light, and the tip doesn't protrude much from your ear, which makes them good for wearing under a beanie or hat during winter, and it makes them very suited for using while lying on your side - they don't protrude from the ear.  Also, wearing them for extended periods of time is likely to be comfortable.  However,  the flat cable has its ups and downs - while they provide hassle-free use, the weight of the cable is quite noticeable - the cable tugs on your ears and will easily come out, and doubly so in the case of the right-hand side, due to the weight of the microphone.  Also, due to the weight of the cable, it's quite noise - move around, and you'll hear the cable bang against your cheeks.  While this can be partially remedied by wearing the headphones behind your neck, it's not a complete solution, and it makes the built-in microphone and volume control next to useless.
That being said, the microphone is quite good - I've used my a-jays as a handsfree solution, and the microphone is pretty ergonomic - the volume buttons are placed on each side of the play/pause/answer button, and the buttons are differently shaped, so you can tell which button you're about to push without looking at it.  Also, the microphone is usable in many conditions without having to hold it next to your mouth, even in outdoor and noisy scenarios.
So, what about the sound?  Unfortunately, this is where they fall completely flat.  First off, even with the rated impedance of 16 ohm, they are not particularily easy to drive, with a rated sensitivity of 96 dB. Next, there is the frequency response - I have pretty average ears - and have used any number of in-ears in the past, all of which have given me a seal with the medium/standard-sized silicone tips.  With the a-jays, I never got the distinct impression that I had a seal.  I could clearly hear the world around me still, and I was unable to get a proper seal even with tips that have given me a good seal when mounted to other headphones like the Sennheiser CX-300 II and CX-380, Sony MDR-75EX or the Nuforce NE-700X's.
At low volumes, the mids and highs are very pleasant. Not overly detailed, but not lacking either, and they are without any perceived peaks or dips, which means they can be worn without causing excessive listening fatigue.
But, as said above, the lack of a seal means that bass is extremely restrained, to the point of very nearly being absent.  While this can be partially remedied by simply turning up the volume, that is not a good idea, because as soon as you turn up the volume, the once pleasant mids and highs takes on a shrill quality, like someone screaming in your ear.  
And even if you do get a seal, this aspect of the headphones doesn't go away. When I forced a seal on them, by wrapping them, and then wrapping my earlobes over the ear canal (Yes, they do protrude so little that this is possible), the bass is still anemic.
That being said, what little bass there is isn't muddled or heavily distorted. It's there, but even if you're not a bass head, it's just too thin.
Also, the low sensitivity, and low isolation level means that as soon as you venture out of your office, you will have to turn up the sound in order to get acceptable listening levels, which leaves you with the shrill mids and highs. The unpleasantness of this sound has occurred on all devices I've tried it with: two laptops (Lenovo X201 and an MBP), an aging Sony Walkman MP3 player, the iPhone 4 and the first and third incarnations of the iPad.
So, in conclusion: Would I buy these again, or recommend them to a friend?  The sound quality is, due to the lack of seal, low sensitivity and anemic bass not much better than the default Apple earbuds, and while the cable is the most hassle-free solution I've come across, it causes too much noise when moving around.  So no, I suggest you look elsewhere.