These are good but they have problems. I'd like to start by saying you are paying for the wireless technology not the sound quality as many non wireless earbuds have much superior sound quality for cheaper price like the carbo tenore, with that said i have had these for 5 months now and while i like and still use these some of the problems have become apparent.
My main issue The poor design of tube you put the tips on makes the tips stick in your ear or just fall off when not in use as there is no lip to keep them on, this wasn't a problem for the first few months and it only seems to happen to the silicone tips not the comply/foam tips. This is also a known issue a simple google or look on the jaybird forums will show you i hope they redesign the tube for the x4 as i wont buy another pair of the x3 when these break simply due to this problem.
Sound quality Like i mentioned at the start the sound quality is not amazing for the price however it isn't terrible and the equaliser app lets you change it to your liking which i recommend you do as the default is rather flat. there is no tininess and the bass is present but you can get better quality sound if you don't need wireless
overall they are fine i doubt you can get better wireless earbuds for this price but know what your getting