I've been a fan for over 20 years. The Savage 60 (MKI)) was my 1st tube amp. Sold it to fund the purchase of a new Invader 100, but 10 years later I got a used Savage 60 again; I use the Ironball for rehearsals at locations where I don't know what dodgy (H&K Warp factor anyone?) heads they have and I have something decent and light to carry around.
Never had reliability issues.
There's a few models I don't care for at all; like others already suggested, the Powerball I is a turd. The II is a big improvement.
Owned the SE EL34 for a while; and yes, it does crush and slam hard with more (controlled) gain than even a 5150III, but it's the gain boost steps that keeps it, IMO, from being the 4 channel amp that I hoped it would be. The Invader does that better. Sure, the Invader should've used Lead II from the SE on its CH4 channel, because the Invader's CH4 is way too smooth and saturated, in this charicature of a Bogner sound perhaps?
For a more brutal metal approach, the SE would be the better choice than the Invader, but for a really all-round 4-channel, 8 sound thing, where you have to do classic rock and hard rock as well, the Invader is the better choice IMO.
Cleans on the Invader are amazing, maybe not as responsive as a Mesa Mark's clean, but great nevertheless, for that true clean sound from a high gain channel switcher.
And yes, a few do sound overly processed. Not the old Savage IMO. It sounds more raw and pissed off. Compressed, sure. Just not synthetic/processed, like the Powerball does.
Oh, and when I had the SE, I replaced those god awful chrome knobs, that are impossible to read on a dark stage. See attached image.
Savage knobs (and brushed Engl logo) were their peak in terms of function and design.