Preface: I am new to digital painting and have also only experimented with the program for a little more than an hour. With that said.....
This program is amazing and exactly what I was looking for that I never knew existed. I read in one review that there are only "a limited amount of brushes"--actually the exact opposite is true. The entire point of this program is to offer the users the potential to create an infinite complex of different brush types. It's not set up like a photoshop or anything, but I don't think it is meant to be... If you get creative with your use of your brushes, you should be able to create any effect you can imagine. Or you can make a great painting and finish it off on gimp or PS.
I look forward to being creative and seeing where this program allows me to go, what boundaries I can push. SUPER FUN TIME.
Honestly, compared to other programs that actually do have limited brushes and are probably a lot more expensive, to say this is a steal is a large understatement. Get this ♥♥♥♥!