I've got one. Bought it for touring so I always had an approximation of how I want to sound wherever I went and whatever I borrowed (we don't have the cash to fly our normal gear around). As a pedal, it's a bit boring, but use it like a preamp, run it into the (hopefully tube) power section, and it's not too shabby, depending on your tastes. Plus it fits in my guitar case! Not an amp substitute, but as a backup, it's worth it.
Mostly though I just use it for jotting down ideas into my pc. Add some reverb on the way in and it sounds almost like an amp. Not really, but good enough for pre-production stuff.