It's superb - works very well with Sony ACID or Sonar.
I get similar results with just this box to a friend of mine, who has a pair of PodXT Pros and a spanking new Edirol interface, costing 10 times the amount.
The amp modelling is good - amazing for the money, especially when you consider it does Bass and "normal" guitar - and vocals and keyboards on top of this! You couldn't get a reasonable amp for this price.
The effects are just OK, but there's plenty to choose from - and again, you can buy a single effects box for the same price as this incredible piece of kit - and besides, I do most effecting via VSTs like any sensible person.
Coupled with an SM-58, it gives reasonable vocals (although a condenser would probably be better), and teamed up with an SM-57, you can get reasonable live recordings of your axe through your favourite amp.
Those are the only 2 mics I own, and I imagine that you'd get better results with better gear - but haven't tried, so can't vouch for any limitations of this awesome little box.
Now, somewhere around here I have a sample of music I produced using it... it's in the "Bash this recording" section at the moment... enjoy
