I discovered ArtRage not too long ago, and it seriously rocks! I'm going to buy the complete version very soon (still can't believe it's that cheap, that must be the better quality/price ratio ever).
A few simple and easy suggestions that would make my life easier:
- add a ctrl+spacebar shortcut for zooming (you already have space for moving the canvas, and alt+space for rotating... where did the zoom go??!). This is because I'm not comfortable with the right click/right+left click for panning/zooming (it's doesn't feel natural for me with the tablet's pen).
- either give the possibility to remap the keyboard shortcuts, or at least offer the possibility to use different keyboard layouts. I use the english version of the software, but with a french keyboard, and that makes some shortcuts a bit silly or difficult to use.