They've stopped making these apparently, now that the V-amp 3 supercedes it. But i got one yesterday - basically just for playing the guitar with headphones - the sound is brilliant! You can turn a knob and it gives you loads of different amp sounds so that your guitar sounds like a warm bluesy valve amp, or surf rock or heavy metal. Another knob selects all sorts of effects. There's a reverb knob as well, plus gain, bass, treble etc. The Wah wah effect sounded good, plus i liked the various echoey ones and I tried out the tap button, which seemed to work - you can tap the rhythm so that it echoes at the right speed - like U2 or something. You have a knob to vary how much the effect comes in - there are a lot of knobs!
There seem to be loads of output and input sockets, plus it comes with a sturdy canvas bag and foot-pedals.
If you bought all these effects separately you'd pay a fortune. I don't know why you wouldn't want one of these - it is great!