A tablet is a tool, nothing more - you only need it when you need it, like a screwdriver. As Joe mentioned, you will probably need it for sculpturing and modeling apps - the stylus can detect the amount of pressure used which lets you finesse small movements. Similarly, you need this degree of control if you are putting together special textures or use "airbrushing" techniques as part of your post-work. If you are mostly assembling scenes with canned objects and textures, a mouse or trackball is probably better. I have a tablet and don't normally use it - but if I'm doing any of the aforementioned things, I NEED it and gladly use it.