... while the 265 may be step down from the Galibier, Reven, your 320 (and maybe SME?), would it still be a step up from my Scoutmaster considering it allows me to change the tonearm?Yes, I'd say so.
Being able to use a TriPlanar is a notable step up.
Resonance control will be better. We never had your "ringing" with our 265. The 320 provides even blacker backgrounds, but the 265's no slouch.
The motor is good, though not quite as quiet or as powerful through transients as our Reference II motor. (There were QC problems from the motor supplier on some Reference II's, one reason Chris doesn't sell 320's any longer.)
If you go with any Teres or Galibier belt drive, the belt we use is a huge improvement over the stock belt. Also, last week we found a $60 tweak to the battery power that makes a major improvement in both background noise and dynamics. Our system now sounds notably better than what you heard.
Speaking of cheap but effective tweaks, I agree with Thom. You're going so fast (fun though it may be) that you're missing chances to learn. Example: you sold the Alaap largely because its harmonic richness overpowered other components (apparently including the VPI). We both know that wasn't the Alaap's "fault", and when you get a non-ringy table you may miss it. You'll never know how good it would have sounded (unless you buy another one). I'm not suggesting you have to like the same preamp I do. I'm suggesting you have no real idea whether you'd have liked it or not. All you know is that it showed up minor flaws in a pretty good vinyl rig in a major way, and that it doesn't do so with other rigs.
Upgrade one thing at a time, and don't upgrade it again until you're sure its a WEAK link. Take time to learn what your components can (and can't) do.
Care to guess how many TT's, tonearms, preamps, amps, wire and speakers we've had in six years? Just two of each, roughly one major component upgrade every six months. There've been a zillion minor tweaks in between, many of which have provided improvements as big as any component change (like our new battery charger). But those tweaks would never have happened if we'd been swapping gear so fast we didn't have time to understand it.