Well, here's a firsthand report. I have QS3r's on the winder and Elka stage 4 on the Viper and this report is from riding all last week (6 Days and 1500 miles). With the QS3r's I had the fronts revalved and couldn't be happier with the results, I was finally able to use all 3 settings. Also had Elka dual rate springs installed. The rear shock I had the rebound side sped up as stock is to slow. The center shock I replaced with an Elka stage 4 with dual rate spring as well. Two reasons for this change on the center shock, first the OEM QS3 does not have rebound and second the dual rate cross over collar wears on the kashima coating badly (been there done that). Lastly, I upgraded the torsion spring for my weight. I set the sled up as per Accelerated Technologies recommendation, leveled the front arms and pulled the limiter straps up (like 3 holes). So on to the ride, the winder improved in all areas, comfort, handling, easy steering, stability and quick-change ability to trail conditions. Prior to all these changes my foot would bounce on the running board in the stutters now I don't feel the stutters. Handling wise it's glued to the trail with no inside ski lift, and I don't have to apply footwell pressure to the outside ski for bite. Comfort comes for the shock springs; dual rate springs really take all the trail chatter out of the equation. Part of this is getting the center shock to stop creating a fulcrum in the sled. I have zero preload on the center shock spring, like a turn/turn and a half from loose. When the trails are smooth, I would slow down the rebound and speed it up if the trail turned choppy. Ok enough on the winder. On the viper I replaced the stock QS3's (not r's) with Elka Stage 4 all the way around. Dual rate springs and torsions just like the winder. Sled set up the same as well. Tuning the Elka's is different with having more adjustability, but the results are pretty much the same. Same comfort, handling, stability and steering. Both shock packages performed flawlessly, it would be very difficult to choose one shock package over the other. I would take either one, but the QS3r's will need some TLC to make them as good as the Elka's from the factory.