i have both the TyTN (cingular 8525) and the Vox in my hands.
I had the TyTN first as a replacement for my treo 600.
The TyTN is a wonderful device, but a bit too much for what I use it for (I dont even use data, so 3G doesn't matter to me). I mostly use WiFi for the occasional browse.
The TyTN definitely has a larger customization factor, which i miss with the Vox.
I thought speed would be a definite difference, but if you use OmapClock to ~250Mhz, it's a significant increase in performance.
Video playback works real nicely with TCPMP on the Vox too. Some video's i don't even need to convert. It may not be as powerful as the TyTN, but it's sufficient for my needs.
I like the Vox formfactor a bit better. The slider is much more secure, and the numeric keypad is something i missed on the TyTN.
Sometimes i catch myself tapping the Vox, forgetting there isn't a touchscreen, but the menu's and programs are very smartphone friendly, and I haven't had any problems navigating menu's as yet.
and for some reason, the screen on the Vox seems a bit nicer than on the TyTN. could be because the TyTN has the same resolution, but larger size, so it doesn't look as sharp.
i'm keeping the Vox, anyone want a TyTN?