Here in Quebec many etec 800 and 1200 run CvTech.
The Ski Doo QRS secondary when calibrated properly is extremely good & very durable.
800cc twins are bad for torsional vibration, they eat themselves It's taking since 2001 for Ski Doo to get some form of durability & reliability such as the 800 E Tec. Part of that is from the Dampener & ring gear which is part of the TRA drive clutch. You remove that & take away where those destructive forces are absorb. That aside it is a very good clutch when calibrated correctly.
Ski Doo clutches when correctly set up work very well. In the early days when other clutch manufacture's were trying make their mark they always compared their clutches to stock factory set ups.
Factory calibration from Ski Doo in the Mountains prior to the 2013 XM....horrible. Then they were very good until 850 E TEC G4, horrible....BTW I've a fix for that sled now.
I would & have tested other clutch manufacturer, my rule was that we compared to my best calibrations. I'm not saying the others weren't any good, when I set up the stock clutches correctly their was no reason to swap the clutches out.