I personally prefer the SQ of the X2 ... lots of clarity and detail, I find the X3 a bit too smooth for my liking. The UI is no frills but easy to get used to. I found no probs in upgrading my FW but I'd have thought that if you buy one now it will have the newest FW version anyway. there have been no FW updates for X3, there were 7 for X2 I think. The X3 was rockboxed and that fixed almost everything. you may prefer rockbox UI and functionality.