Rega RP8 or Technics SL1200G

OK...

Rega recognizes that coupling between the base of the arm and the platter bearing is important. Given that, they seem to be trying to save weight in the assembly, which would  seem to fly in the face of the rigidity aspect. IOW the Technics is **more** rigid in this regard (employing a plinth and a case subchassis) and also more dead (employing 4 different damping schemes in the plinth/base assembly).

A powerful drive is an important aspect of any turntable. In this regard you can see that all the well-regarded vintage machines (SP-10, Lenco, Garrard 301, Empire 208) have powerful drive motors. This makes a difference when dealing with needle drops and bass tracks- the speed stability is greater; the improved speed stability is not audible as pitch but you can hear it in terms of image stability. Its not enough to have a massive platter. The Technics has a decent platter (which is also damped) and a much more powerful drive then the PR-8.

The tone arm of course can't be overlooked. The Technics arm, while looking the part of its earlier version, has improved bearings and arm materials, as well as the benefit of improved machining. You can adjust the VTA on the fly. Its hard to tell about the RP-8, but IIRC its does not have a VTA adjustment. For this reason your cartridge selection is limited.

Two items to consider.  Is the RP8 die for an update?  The difference between the RP6 and P6 is substantial.  Also something to think about is your listening space and isolation.  The SL1200G won’t need the same level of care and placement as the Rega.  Two small points in an otherwise difficult decision.  My feeling is that the 1200G is superior technology over the Rega.  

Here is Fremer's review of the 1200G. The 1200G is also an Absolute Sound Product of the Year in the January 2018 issue.

Pretty much every review I've read of Rega TTs that measures rotation speed indicates that they run fast, whether it's an RP3, RP8, or something in between. Since the brand has been consistently (slightly) fast for years, I suspect it's intentional. If I were to guess why, perhaps to compensate for a low-torque motor combined with a stretchy belt.

A high-torque design with great speed consistency has notable playback advantages, particularly maintaining tempo and volume in the face of higher groove modulation--modulation that accompanies louder passages and/or a higher number of voices and instruments.

Thanks everyone for your comments, they have been very helpful. 
@johnnyb53 , I've read both of those reviews, also one in Stereophile.
One thing that no one has mentioned is the dreaded Rega hum. My P3-24 suffers from this malady through the TTPSU, I believe. It's not noticeable during playback, but it is there while idling. I'm leaning towards the Technics. I'll make a final decision after the first of the year. Thanks again.