Hey, perhaps consider the Cowon Z2. I love mine, but I don't know if it outperforms the Walkman Z (in terms of what? Sound? Build quality? Features?). Anyway, here are my thoughts:
The Z2 is not warm at all, but very detailed and has no particular frequency bias that I can tell. Some complain it sounds cold and boring, but the EQ suite is effective and should fix that pretty quickly should you want excitement. Clarity is great, I have no official stats to roll out to convince you (I don't think output impedance is below 1 like some other players, but I've never had problems with IEMs and there is little to no hiss) but I go with my ears and boy, these sound really nice!
I bought mine in the US from Amazon with a screen protector and case and I couldn't be happier with my new DAP - features-wise, it competes more with an old iPod Touch, as it lacks a camera and GPS, etc.. It browses the web fine, and has more features than your typical mp3, while apps can easily be added if you want more configurability.
In this (Apps) respect it is probably not as nifty as the Walkman Z, which I understand runs on Android 4.0 and has a much better processor for all the new Android stuff as well as a better screen (the Z2s is very nice AMOLED, but doesn't have a blazing high resolution), but I can do with it given that the Z2 makes my music (and headphones, which are warm and complement its analytical sound well) sound great. As a bonus, it has a micro SD slot, which takes 64GB cards if you want lots of lossless music.
Things to consider: It's on Android Gingerbread 2.3 (but it does have access to the Play Store, which I really like so far), battery life is short-ish at 22 hours audio (I can get 20 hours easily, though I often charge it before) and has no Line-out Dock for amps - I just use a micro interconnect, but some say this is audio sin.
Since you're in China you could check out some of the more audiophile DAPs from Colorfly and Hisound, but as my all-around media player which sounds-pretty-good, I'd pick the Z2. You lose a few things, and gain a few, so weigh them up, and best of luck...
EDIT: +1 on the iPod Touch 5 purely in terms of the plethora of features, the battery life and the great screen. I haven't heard it extensively yet though, so I'll defer to the iPod experts...
Edited by StyleElements - 1/28/13 at 7:57am