So, now that I've actually used it for a couple days and have fixed the problem I was having with the tags, I'd say I'm pretty happy with the purchase. The interface is smooth, with no lag. The media scans on just a normal start up are normally done in like 10-20 seconds, but can take much longer when you've just put new files on it. Sound quality is great, as expected. I haven't experimented much with the jeteffects yet, but I made them match the settings I used on the J3 and despite that, they don't sound identical. I can't say yet whether it's better or worse or just different. The handful of games I've put on there so far (including Angry Birds) work great. The screen looks amazing, but I don't know if I have any movies that really take advantage of it. Wifi and web browsing are functional, but since it's a touch screen, typing's not as easy as an actual keyboard. Battery life is pretty good. After playing music for about 6-7 hours (all ogg/vorbis) I was at about 55%.
Two things I'm not the hugest fan of:
When you have the screen turned off and are listening to music, you can use the tactile buttons to pause it, but you have turn the screen back on and unlock it in order to make it start playing again.
I'm coming from the J3, which lets you go in by artist tag, then shows you all their albums as well as an option to just play everything by the artist. With the Z2, if you choose an artist, it just shows you all of their songs rather than showing you a list of their albums, meaning if you want to actually listen to an album, you have to go in by album tag instead of by artist tag.
Other than that it's been pretty great.