I have an '03 Classic 30 which I purchased used (with modifications) about three years ago. It was my first real amp, it has JJ tubes and an attenuator added to it by the previous owner. But it's a solid amp that sounds great to me. And even though my Fender Deluxe VM has taken it's place as my go to gig amp, I don't plan on getting rid of the Peavey. It has a much different sound than my Fender, and I like having either of the tones to choose from.
As far as the construction of the Peavey goes, it's built better than any other amp I've ever seen for the price. I have a '79 Peavey T-60 guitar, and that thing is a tank. If you dropped a nuclear bomb on Houston, my Classic 30 and T-60 would make it through unscathed.
If someone digs them up 1000 years from now, they're still going to work. I gigged with mine for two years and it never once failed me.