Tone wise they're very versatile. Depending on setting it can do almost anything. Throw in a boost and an EQ and you can get some damn brutal tones.
Switching wise, not so much. To get a lot of gain out of it, you sacrifice the clean with the 'boost' turned off. If you run totally clean with the boost off, you can't get much gain. etc.etc. If you're looking to switch between raging metal gain and jazz clean, I would go for a VH100R instead, as the gain channels are 99% the same, but the VH has a dedicated clean.
Also, I would run the treble very low, or off, and use the presence as a high knob. The amp sounds, and responds, better this way for many people.