I had a Metaltronix m-1000 and worked at a store that sold them in the early 90's. Amp could be made to sound like Ozzy's no rest for the wicked very easily. It also could sound like the first Mr. Big album, which I thought the tone sucked on that one by the way. What I wanted it to sound like it couldn't seem to do, and that was to sound like the racer x stuff on the first and some of the second album.
I had a friend that had a marshall 50 watt modified by Lee that could could cop the heart of a lion sound perfectly, but I could never get that from the Metaltronix. I had it for about six months and after the second transform blow-up I got rid of it. I don't blame the amp on the blow-up, I think that it was so loud that it damaged several speakers in my stack which f'ed up the impendence (I didn't find this out until after I got rid of the amp). I will say we had a lot of returns for problems with them at the beginning. Once the blue model came out they seemed to be fine. I did try out the ampeg versions some time later and thought that they actually sounded better, but I've never used one enough to say for sure.
I eventually traded some gear to my friend to get the PG mod Marshall 50 watt which I still have today sitting lonely in the unused gear pile (although it does sound cool).