Does anyone have any opinions on Cinepaint as a tool? I’m starting a small animation business and want to know if it’s good enough for matte/texture painting. I’ve heard mixed things so far. Any thoughts?

Cinepaint sucks. I can’t get it to do anything other than crash. If you want something free stick with GIMP.

cinepaint sucks. Stick with Gimp if you want free. If you don’t like gimp, just buy Photoshop

Well, Hollywood’s already using it. (See the cinepaint homepage for case studies)

To be honest, it’s not the prettiest app to use, but it does what it does solidly.
If you are planning on doing film work, (i.e. using deep colour) you will need something like this.

Since it’s free, why don’t you just download it and give it a try?