For the price, this box is unbeatable. I was flat out amazed by what it could do. The dirtier tones seem to suffer from a bit too much high end, but judicious use of the EQ section helps tremendously. The clean sounds are great. The sounds are sometimes noisy, but they have a very good NR system and you can dial the hiss right out.
Distortions are the noisiest.
I haven't tried it with an amp yet, because as a simulator, I am using it as an amp substitute. To be honest I've had this for a month and find it has some pretty cool patches to use for my home recording projects. My least fav. But there are level adjusts to warm them up to be fair. I want to try this with my Fostex X-30 and use it for the bass it gets a nice sounding phase for bass, and not as dry as direct.