Short summary for people who don't want to read detailed review:Great IEMs with punchy and powerful bass, clear mids and okayish highs. The build quality is great and they look awesome (I got the one in red color). How comfortable they are will depend on person to person, but I felt they I could wear them for extended periods of time without any problems. The sound isolation is decent, but its not enough to isolate the noise of a subway train when you are traveling.If you are looking for cheap IEMs that wont break your bank but at the same time can be your daily driver and sound outstanding, these will be the right fit. If you are looking for critical listening, then maybe its worth looking into more high end IEMs.****************************************************************************************Detailed review: Let me get the secondary stuff out of the way first.I've had these for about two years now and I don't have any complaints so far. The build quality is superb - I like that these wires dont tangle and are strong enough to withstand fairly rough use over these two years. The cable noise is noticeable. The microphone is okayish - I prefer not to use it to take calls. The color on the housing of these IEMs has started coming off (as you can see in the picture). The quality of silicone ear tips is great - I never had to replace them and they feel comfortable sitting in my ears for extended period of time (8 hours+). The sound isolation is fine but not enough to fully isolate the noise of engines when taking a flight or the sound of a subway train when traveling for work. Maybe it would be worth investing in foam ear tips that conform to your ear canal for better seal.Now coming to the important part - the sound quality. This is where these IEMs excel.You wont believe how good they sound for the price. I mean I open the packing, take these IEMs out, put them on and start listening and I am immediately impressed by how detailed the sound was. The bass on these things is amazing. Its punchy and powerful, but it doesn't overpower. I am not a bass head - I try like to listen to music exactly the way it was intended by the recording artist. The mids are clear but the highs are a bit lacking. For example, it is sometimes hard to hear piano or cymbal sounds when there's a lot going on in the music (listen to 'The Fire Within' by Jennifer Thomas and you'll know what I mean). I mean you can imagine - I am reviewing these earphones as if they are priced at $300, they are that good.So I looked up the frequency response curve for these IEMs online and I notice that obviously they are tuned to produce enhanced bass. But at higher frequency (5000 - 24000 hz), their response is lacking considerably which means its sometimes harder to distinguish sharper sounding instruments like cymbals or crisp sound claps. If you have critical ears, you will always feel that they are very good but something is lacking...I recently got the 1more Triple Driver for $80 (more than 2.5 times the price of the XB50AP) and when I compared the XB50AP to the triple drivers, I found that the sound from XB50AP is comparatively a bit muddied and shallower but only after I had to really sit down in a quiet environment and listen carefully. The 1More triple drivers are THX certified for its Hi Res sound and are usually compared to the likes of Shure, Sennheiser, and other high end earphones - and the XB50AP comes very close to the triple drivers for 2.5 times less the price.Honestly, you wont even notice all this unless you are listening very critically. If you are the kind of person who just wants really great sounding IEMs without breaking your bank, then go for these without any doubt. They look stylish, sound really amazing, feel comfortable, and are very durable. For about $30, these things are a steal.