ArtRage for UltraMobile devices has exactly the same functionality as ArtRage 2.2 Full edition. The only difference is some of the UI has been optimized for small form-factor displays of around 800 x 480 pixels. If your display resolution is higher than that (1024 x 768 or better) you may as well get ArtRage 2 Full edition.
The Full edition of ArtRage is at version 2.5 now, while the UMPC version is still at 2.2 (because it takes us longer to do the User Interface optimization for the small form-factor displays). The non-standard versions of ArtRage will always slightly lag the standard Full edition in release dates.
AndyRage's mantra for graphics engine code:
"Sure - how hard can it be?"