Gradually, I found I wanted more bite out of the 5150II, so the mids came down and the treble and presence gradually went up which chocked the tone of the amp so the amp kinda stopped working for me anymore. Also the low notes on my 7 string were becoming a lost cause so it was time to look elsewhere. The Blackmore is a crisp, brighter sounding amp with a much tighter feel to the bottom end. Also, the amp reacts better to the guitar when you turn the volume down or change to a single coil setting. It actually sounds like a single coil, which didn't really happen on the Peavey. It's more transparent I guess. I don't use as much gain on the Blackmore as I did on the 5150. The amp just seems to have more balls and power to carry the sound, rather than relying on sheer gain!. In my search I've gone thru Mesa's, Soldano's, Peavey's and Cornfords before I found this amp, and it's awesome!!