A bit late....
Hahaha I am a bit late on this one, but all aspects of USB OTG are functional on the Desire X w/ stock and some custom roms. This includes storage, keyboard/mouse, gamepads and much much more. Works flawlessly, and better than the Nexus 7 2013 on Stock can manage (no usb storage support!) One of the reasons I switched to CM 11 on my Nexus.
(falcon) Moto G (XT1033 AUS) (Stock) (Rooted)
(flo) Nexus 7 FHD 2013 (AOSPA 4) (Rooted) (Franco Kernel)
Other Android Stuff:
(protou) HTC Desire X (Optus AU Variant) (AOKP) (Rooted)
If my post assisted or helped you, feel free to hit the thanks
button! Or don't