Dgarretson - As Doug points out:
"According to emails from Chris, the performance jump vs. belt drive is inversely proportional to the weight of the platter. Lighter platters have less rotational inertia, so they benefit most."
Presuming this holds true, in terms of yielding improvement, the lighter platter would to a higher degree - so this may be the more bang for the buck solution. However, in terms of overall sonics there is enough difference between say a 255 and a 320, apart from the drive system, that the latter easily bests the former by a pretty wide margin - at least to my ears. The inertia of the larger platter coupled with superior isolation provided by Stillpoint dampers make significant contributions to speed stability and lower noise. When I upgraded from a 255 to a 320 I definitely expected improvements, but the 320 significantly exceeded my expectations. I would be quite surprised if a 255 with Verus could exceed a 320 with the Reference motor.
Over time, I've found my skepticism about Teres improvements consistently disappointed, and Chris' assessments to be quite accurate. Of course I'll wait to hear the Verus and judge for myself, but I have no reason to doubt that it will be an improvement commensurate with the upgrade price. We'll see - I hope the Verus starts shipping soon.
Tim