Pros: Very comfortable; Tiny; Smooth, relatively clear and non-fatiguing sound signature; Inexpensive.
Cons: Not very sensitive; Poorly designed cables; Poor strain reliefs; Useless carrying case; UE tips can become loose over time.
Why another iem?
The Creative EP630 was my 'beater' pair of iems- ie, a pair I used for casual and rough use. It was no SQ king, but it served me very well- it was more than 5 years old (IIRC) and it was still working when I gave it away to a friend. Now I didn't have a beater pair to use. I use the W4-s during my long commute and while studying, the Grado SR60-s when I don't feel like using an iem and my bro uses the Pana HJE900-s. I had my eye on the UE 500 while I had been shopping for an iem earlier. I saw that it was going really cheap on ebay and upon seeing that the seller was legit, I pulled the trigger on those.
Packaging, Build quality, Accessories
I found the packaging to be really cool. Quite elegant. Okay.. the accessory bundle wasn't too big- but all the essentials were included- a good selection of UE single flanges, a pair of Complys and a Logitech branded clam-shell carry case. The iems itself turned out to be a bit of a disappointment for me in the fit and finish department.
First off- the cables. I've got only one word for these- ****ty. I had read that the 500's cables were bad, but I didn't think it was this poor. The flat cable design and the tacky prints look cheap. I'm sure that these cables would stiffen and crack with time. They are microphonic too- every time they rub against your clothes..aargh. This can be solved to an extent by wearing them over-the-ear and using the cable cinch to hold it in place.
Next, there aren't any proper strain reliefs- either at the place where the cord exits the housings or at the 3.5mm plug (which is pretty sturdy, btw). Many people might not have an issue with the cable design or the strain reliefs, but I've been spoiled silly by the most excellent W4-s braided cables. It's not a fair comparison, but I've seen cheaper earphones with better designed cables than the UE 500.
Lastly, the chromed plastic housings. Lot of bling, but I don't like it because it can attract stains and oils quite easily. Quite a subjective opinion- feel free to disagree here. On a positive note, the housings are tiny and appear to be well made.
Comfort and Isolation
These things are really comfortable- aided in no small part by the small housings and the soft UE single flanges. The isolation is pretty good too- not as isolating as the triple flanges in my W4, but it comes close. The drawback with the UE tips are that they become loose over time- an issue my brother is already experiencing on his Pana HJE900 (he uses UE tips on those).
Bass: Strong, not at all boomy, extends very well, has lots of slam and air, good impact. The bass is not a prominent part of the sound signature, but when called for it can be powerful, deep and impactful. The bass quality and presentation isn't natural like the Pana HJE900 but the UE 500 costs less than half of the Panas and I have to admit, sounds more enjoyable too- especially for casual listening and while watching movies.
Mids: Would have been slightly recessed if it weren't for the mid bass hump. Smooth, in offensive and non-fatiguing. Guitars and vocals sound clear- but do not jump out at you or envelop you with its warm, liquid smoothness like mid-focused iems.
Highs: Extends well and isn't harsh or sibilant. Smooth and relatively detailed. No complaints at all.
Sound staging: Wide and airy. Must be the widest among all the phones I own, as a matter of fact. Positioning is good and so is the instrument separation. There is no sense of intimacy for the tracks that demand it, though.
The UE 500 has a v-shaped sound signature. Unlike the HJE900, it isn't as drastic- it's only mildly v-shaped. The overall impression is that of a smooth, relatively clear and likeable sound signature.
A big drawback of the UE 500 is that they are not very sensitive. I need to go up to higher volumes on my Clip Zip to drive these things properly. Hisses a bit when connected to my LG Optimus 4X- none with the Clip or my laptop.
For the price I paid for these, the UE 500 provides good sound quality for the dollar. There are certain caveats like the poor cable design, strain reliefs and the low sensitivity. If none of these are an issue, the UE 500 makes a good buy. However, the competition is stiff in this price range and if you are willing to extend your budget to $100, there are a lot of ace performers in the market. The sound signature and quality is hard to fault, but the feeling of fragility the cables give makes me a bit hesitant in recommending this whole heartedly.