I love the color technique! The final result os "solid", but "cartoon" at the same time!

Are you sure did you setting the tablet right? :)
I don't use Photoshop, but the first time I used a tablet with GIMP I had some troubles, too.
Then, I found out I didn't set up the program in the right way, so actually it didn't "read" the pen :p

Afterall, take your time! first attempt with tablet is always a little traumatic :p