I have one and I love it!
I was in the same situation as you (i got it for $150). For a while I was running a 5150 into one cab, and the VTM 60 into another. When I quit my band, I sold the 5150 and a cab because 1) I couldn't justify having 2 1/2 Stacks and not being in a band and 2) Despite different settings, using a Sonic Maximizer, or using different tube cominations I couldn't get the 5150 to sound how I wanted it.
Honestly, my favorite part of the VTM is that it's 60 watts, so I can crank the master volume, and get my distortion from the power tubes, rather than using the preamp volume.
I agree, it's basically a JCM 800 clone, but it has a series of DIP switches to tailor the sound a little more than just having Bass Mid and Treble.
Here's how I run mine:
1. Schecter Guitar (w/
EMG 85 in the bridge)
2. Clean Boost
3. Pedal Board
4. High Gain Input on VTM (Preamp @ 4 - Master @ 6 - Bass @ 5 - Mid @ 8 - Treble @ 5 and of the DIP Switches I only use the compressor)
5. 1976 Marshall Mark II Cab w/25 Watt Celestion Black Backs (these are Greenbacks before they had the green label).
I think you can get a lot of good sounds out of this (thanks to the DIP switches). I wouldn't say you can only get a 'classic rock' sound of it. I've seen a lot of people in the past using them for everything from Blues to 'Screamo'. I even saw a harmonica player using one for his harmonica, and going into a cab w/a single 15" speaker in it.
Here's a link to the manual from the Peavey site
http://www.peavey.com/support\searchmanuals\list\vtm60_120.cfm
Curtiss