VSONIC GR07

Gr07 is perhaps one of the best IEMs around in value/price. They are balance and just about every Genre i listened with them ain't bad at all. You can't go wrong with them. The only issues one might have is the fit, and the earguide

VSonic GR07 is a great example of IEM strong because it has few flaws and almost all of these are possible to correct with a good equalizer.
Bass is perfectly controlled, excellent texture, very well extended (-6 dB at 30 Hz with perfect seal), perhaps a bit warm due to high-bass boost (~250 Hz). No bass bleed is present.
Mids can be slightly forward to slightly laid back depending on tips and depth of fit.
Highs... here's the issue. With shallow insertion, there can be a fair amount of lower highs boost, around 6kHz, which combined with some highest end peaks can sound sibilant. Using foam tips helps with this, deep insertion completely removes this issue. GR07 don't have a lot of energy at the highest end, but they do have extension, so it can be corrected.
Timbre is excellent - delicate and unassuming, with excellent detailing, not overly aggresive and not overly smooth.
Soundstaging depends on depth of fit. With shallow fit, the soundstage isn't the widest, but is quite competent - with minor positioning issues due to sibilance and high-bass boost. With deep fit it is perfect, both width and depth, there's vertical resolution too - it will unfortunately make all recording and mixing flaws in this regard obvious.
Fit is excellent both for deep and shallow insertion due to rounded edges and no molding artifacts, small enough size and adjustable nozzle angle as well as a fairly large tip selection. GR07's nozzle is unusual sized though which limits possibilities. For Comply foams, T140 is the correct size.
Isolation is good for dynamic driver IEMs, microphonics are nonexistent.
Cable doesn't tolerate any kind of rotation around the axis of the cable for the part above Y split. If any is present, the cable tends to jump off the ear. This is easily remedied with the included ear guides or neck cable adjuster.
3.5mm L-shaped jack is iPhone friendly and seems very sturdy.
Build quality is very good with a minor exception - the strain reliefs tend to come apart from the body of the IEM. Easy to fix with a dot or two of superglue.
GR07 are efficient enough to be driven directly from a portable, do not gain a lot of quality when amplified.
 
Their main problem is availability - there are few sellers and those can be a bit remote.
 
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Now that my RE272 cable broke, I'm stuck with these. They need somewhat extreme equalization to get rid of the presence boost, but with T200 Small, truly a winner.
Of course they're somewhat less analytical, slightly lowpassed (17.5kHz) but beautiful texture.
Without eq they are pretty harsh and "flat" sounding, as in no depth, likely due to presence boost.
Equalization lets them have great depth resolution too.
 
GR07 bass sure is fast and tight, but it has less natural decay than RE272's. Kind of like it's trimmed or slightly compressed. However, vocals are presented far more liquid and with better detailing, while higher end (presence) sounds a bit electric/harsh even after correction.

These are amazing IEMs for the price. It is a balanced IEM and isnt lacking across the spectrum. They can handle pretty much every genre you put through these.
The bass on these is excellent, it rumbles down deep, while being very quick and tight. But the main thing which I love about the bass on these is the 'weight'. When the track calls for it these really do move a whole lot of air and slam it against your ear drums.
As for the midrage, I would say it is neutral, but on some tracks the mids are somewhat warm. With that said.. I'm not sure if the mids are actually warm, or the IEM is just neutral and reproducing warm mids...
The vocals on these are amazing as well. It is very intimate and sweet. These really do make vocals come alive and are also (very) forward (T.V. Carpio's cover of I Want to Hold Your Hand from the Across the Universe OST).
For the treble, I'd just like to say that it doesn't contain enough sparkle to satisfy any treblehead. Despite that, these still contain enough sparkle and detail to satisfy my needs.
Instrument separation on these are also great. I can just 'lock onto' an instrument and it seems like it's the only one playing. A funny remark made by a friend of mine (who is just your typical consumer) told me that he didn't like them because all the instruments playing is all "separated" and not "playing together". (I think he likes to have zero separation and to have a tiny soundstage) 
The only con I can think of is the sibilance. Every lyric that has an 's', (and 'd' and 'th') on some recordings are unbearable. A good example of this would be the song Heartquake! by Sienna Skies.
The only remedy for this is to burn them in for 100 hours. After you hit that mark there may still be some sibilance but they will eventually be non-existant (I have put through around 450 hours through mine). 
 
I am VERY happy with my GR07s! 
 
Here's a list of some of the songs I used to test out my GR07s (all songs are lossless or high quality lossy MP3/AAC):
Perfect Future - Make Fun
Perfect Future - Colonization
Sienna Skies - Heartquake!
T.V. Carpio - I Want to Hold Your Hand [Across the Universe OST]
Joe Anderson & Salma Hayek - Happiness is a Warm Gun [Across the Universe OST]
Papa Roach - Getting Away With Murder
Versailles - Silent Knight
Uppermost - Born Limitless
Uppermost - Satellite
Morgan Page - The Longest Road (Deadmau5 Vocal Remix)
with some classical here and there.