I think it's in the same league, maybe even on the same team, but if the 3x is Babe Ruth, then the 900 is Yogi Bera. It's missing a few things that the big bruthah has, but the stuff that it shares ... well, it goes head to head.
Granted the Harmonizer is a step behind, but still a solid hitter, and the sliders are missing, but if you're fast enough .... who needs to slide?
(OK, enough baseball metaphors)
All in all - for what you DON'T pay in dollars ... you get a solid, dependable piece that sounds fantastic and on any given Sunday .... (Sorry ... switched to football) Does a terrific job. If the 3x had built in speakers - I'd still have mine