Well in my opinion it is better for drawing actual pictures, but for effects and realism, photoshop is better. so its all in how you use them and what you want out of your picture.
Cool, maybe I'll get a chance to try it one day. Right now I'm pretty happy with Photoshop. And whenever I get tired of it, I doodle around in MyPaint.
It's a great open-source digital painting program. It's really good at recreating that whole traditional art feel (something that I think Photoshop lacks). Here's the website if you want to check it out [link]
I've heard a lot about Sai, but never tried it. Is it a lot better than Photoshop?