I've been using my copy of Artrage 2 that came with my new bamboo but it doesn't have watercolour or ink pen brushes so I assume the demo you are using is version 3. Your test results turned out much nicer than mine.

One nice thing I noticed while using it and I assume this carries over into version three - when you start drawing near a tool/info/swatch/layer window/gump, it automatically "vanishes" so you can draw underneath it, and reappears when you stop drawing. Also it has a rotate canvas function like SAI does. I wish photoshop had that (have they added that to versions above CS3?)