Got my Huion 420 Pen Tablet earlier. Here's some feedback I have of it:
- Pen movement feels really responsive, which is great
- I was able to get used to the area in a few minutes (I'm used to full-area)
- Support under Linux seems to be hit or miss. It works fine under Xubuntu 13.10 (fine being the entire tablet is mapped to the entire screen), but was terrible under Kubuntu 13.10 (entire tablet was mapped to maybe 1/5th of the top-corner of the screen; the tablet-config GUI didn't support the tablet either). Could be desktop environment-related I guess? There is also 3 HUION input devices detected, but only one of them seem to accept pointer control settings (sensitivity, acceleration; even though neither apply to absolute movement)
- I'm not entirely certain, but it seems the driver by-default disables Windows Ink functionality on Windows 8.1 (taps don't pause; no ripple effects). There's a setting in the tablet control panel for Tablet PC support, but it's grayed out. Didn't try the tablet without drivers.
- The tablet control panel's pressure meter only went up to 2047; while testing this however, I managed to leave scratch marks on the tablet itself (really noticeable on black; may be less of a problem with osu!tablet)
- The tablet's full area is maybe a few mm off from matching a 1600x900 screen's proportion (according to the tablet's control panel)
- The tablet comes apart easily (4 screws under the rubber feet). Inside of the tablet is really simple (a PCB, piece of thin clear plastic, and a piece of metal). The spots for the buttons exist on the PCB, even though the tablet itself doesn't have the buttons (not sure if the buttons send events or not).
- The indication LED is green (seems to flash every 3 seconds the pen is in-range of the tablet; blinks when tablet surface is tapped and pen button presses)
- The surface attracts and shows fingerprints and skin oil (do note this is a primarily black tablet though; osu!tablet will probably have very little issue with this)
- It handles flawlessly on a metal table (my old VisTablet PenPad had erratic behavior on a metal surface)