I'm using the Brainwavz M2 with a HiSoundAudio Studio (the model name) DAP, and a mini-rig with a Nationite S-Flo2 and RSA P-51 Mustang hooked together with a Zynsonix VRay Prime mini-to-mini IC. It took about 40 hours of use before the M2 were sounding their best - and they are sounding quite good with both these rigs. Lots of detail, beautiful and lush mid-range and timbres, a very spacious sound, and very good bass (quantity and quality). The trebles are quite good as well - really beautiful, without thinness or harshness. I have used Etymotic ER4S for a number of years, and the Shure SE530 for several years as well, and I'd say that the $60 ($50 on pre-order sale) Brainwavz M2 don't have me wanting to reach for the higher-priced IEMs, or my favorite earbuds either. AND, the M2 don't need to go nearly as far into the ear canal to get a great seal and to deliver a really credible spatial presentation of the music as either the Ety ER4S or the Shure SE530. So, I'm enjoying all of that audio quality goodness without as many or as much of the drawbacks (to me) of using the more deeply-inserting IEMs. And, another plus for me, I can make the volume as loud as I prefer (which is < 70 dB at the loudest, BTW), without my cubicle neighbors at work overhearing any of what I'm listening to. In the (trans)portable rigs in which I'm using the Brainwavz M2, they are a real winner in terms of audio SQ and ergonomics with how I listen and work.
