Mike, these things are all a synergy. For me, w Vic the Salvation rim drive tt/Terminator air LT arm designer having voiced these two as a piece, it was a no-brainer to get the complete package.
I've heard my LT arm on a couple of belt drives, and with the mental comparator of my previous SME V that I ran for 12 years, and previous to that, 3 years w my Roksan Artemiz, I have a good handle on pros and cons.
And I would say the heft and "carved from stone" quality of my direct rim drive tt absolutely nails my main genres of prog, fusion, electric jazz, percussion-heavy material.
The LT arm fills out speed and "deftness" extending the rig's abilities w acoustic material, but critically no compromise on bass which is way earthier and tuneful than my old pivoted arms, and critically, lightning fast.
Topping off everything is my LPSd Soundsmith Straingauge cart which absolutely nails timbral accuracy, air and texture.
And isolating the whole shebang from the world, the Stacore air platform.
Throw in nearly 20 other small and big mods, and I truly am in a very content place w my analog, my personal triumph being maintaining total immersion on uber rhythmic music but now also excelling at more airy, timbral-critical, microdynamic music like string qts, solo piano, voice.