Boy was I surprised when I plugged into this monster. You can get mild overdrive to insane high gain, and it sounds GREAT! Definitely knocks the Marshall DSL40 and Peavey 5150 out of the water in my opinion. If you want rich cleans then get a Fender Twin Reverb. If you want to shred then get the HT Club 40. I don't use distortion or boost pedals because the distortion in this amp sounds awesome. Most people replace the stock Celestion 70/80 speaker it comes with, but it still sounds awesome with it in there.
The ISF knob was another selling point to me. Turn all the way to the left left for an American amp sound, or turn all the way to the right for a British sound...or just turn it anywhere in between to mix it up. Makes for a very versatile sounding amp.
Also, if you record at home then you'll love the emulated speaker input. No need to mic the amp. Just plug straight into your box with the DAW you use.
The reverb in the amp is not bad at all, but if you're a reverb junkie then you'll want pedals of course.