Positive is certainly that this player is a 128er Micro SD swallows, unfortunately, there are so far only really fast 32er, but that will indeed change. I welcome also that the NWZ 15 data processed internally super fast. If you have a Mac, you can download the software, but alternatively also use it simple as a mass storage. Why must first switch it on the device to the internal, or use either the DCIM memory, do not open up to me. Cumbersome. Next, I can with the Mac to create any playlists, or I've never found a way to do it. Quite thick disadvantage! Why the well can not do it yourself with the machine, I do not even understand. Photos, radio and comic channels are in my opinion really unnecessary. Bluetooth is again a real advantage, since I use a lot of Bluetooth speakers and also works perfectly. This part works perfectly anyway. Very small, but also rather cheap from the presentation here. Also only one output, well can be enough. Most importantly, the sound, mediocre, I can not say otherwise. Compared to the FiiO X3 Sony reduces greatly, actually, no comparison. mp3's experienced little improvement and also in 16 or 24bit, the player remains in mediocrity. Little balanced, strong tips, hardly anything in the central area, cold and out of true I feel the sound. Compared to Fiio X3 with line out and coaxial output, I find that it does not pay to feed the Sony with 24bit. The NWZ 15 should, in my opinion, cost no more than 150.-. I bought it as a Bluetooth variant, since I now possess much 24bit music. The battery lasts much longer than the FiiO, however, the output volume is much smaller and a little too weak for my taste.