Re: Marshalls suck with gain!
I've been playing through Marshall tube amps for more than 32 years.
In that time I've also owned and played Fenders, Vox, Hi-Watt, Boogies, Budda's, Dr.Z's, Carrs, H&K's and Sovteks and used them all on gigs. I just sold my Two-Rock head and went back to my Marshall DSL100.
NO amp will give you everything you're looking for.
On the other hand, Marshalls have been THE MOST widely copied gain tones ever made- by just about all manufacturers. No other amp has been used by more professional players for overdriven tones. Even Steve Vai used Marshalls for P&W.
I realize the new metal tones require more gain and that there are amps designed for that specific type of music, but overall the Marshall tone is the hands-down pre-eminent Rock sound of all time.
Thank God (or Jim) for Marshall amps.