If you've ever played with FruityLoops (or anything of that ilk) on a PC, you'll be fine with this – it's simple, powerful, and addictive. Even if you're new to music making, there isn't much to be frightened of here.
+ sounds great
+ easy interface with a lot of depth for experts
+ causes time to melt
- might not be for everyone
- song editor might cause frustration
- people around you will lose their minds (not in a good way)