I'd never played a 90s Green Russian Muff (the Sovtek ones), but I'd heard good things about them over the years. I'd never been entirely happy with my other two Muffs. The Double Muff is great for crunchy overdrive, but it's hard to get long sustain out of it. The Little Big Muff does the sustain, but it's just a bit too scooped and fizzy/muddy for me.