I have used Photoshop in it's many incarnations for several years. I'm learning how to use Illustrator slowly, but it's definitely functions differently. I was thinking of picking up Paint tool Sai, I know it's popular with a lot of Japanese comic artists. I do a lot of fully digital drawing.
Can someone tell me what they think of SAI? How different is it from Photoshop? Advantages/disadvantages comparatively?