Another Peavey fan here. I think the main reason is that their Black Widow drive units were (can you still get them?) so good. I replaced the crappy Fender drivers in my old Bassman 2x15 cab with them and the improvement was massive. When I got my TE AH350 in the 80s, the sound of it with the cab was fabulous. Bulky and heavy rig, but wonderful sound.