It’s not accurate enough for me. They’re okay for some things, but if you need accuracy, you should look elsewhere. I’ve seen commercials where people used them for digital artwork, but I think that’s more for just playing around that serious work.
I use a mouse. It’s accurate and I’m used to it. I did use a Wacom tablet for a while, but didn’t like the disconnected feel of it all. Plus, I didn’t find the pressure sensitive tips all that useful for most things. They do work well for painting in Photoshop though. But for photo editing, I just didn’t see a need. A lot of people swear by them and say they’re great once you get used to them. Plus, they’re not crazy expensive. Wacom also makes some computer screens that work with their pens. Supposedly their pretty accurate. But they’re not cheap, which is why I have yet to use one.