Wow Grub...you sure have some issues with your sidewinder.....Everybody knows they are heavy....but honestly, I ve ridden two different models (an rtx 129, and an ltx 137)..both with Fox Iq shocks, and I thought they rode very well for a heavier sled (not as good as an R motion, but not bad)...They are not as light and snappy as an 850 (Ive ridden 4 different 850s)...but don't fool yourself...850s, stock do not run with a sidewinder....it's close for the first 500 feet, and then the winder blows by, and keeps right on going. (we have raced them head to head in the bay out back, different models for each) Unless you run short races, or have a heavily modded 850...you aren't beating a sidewinder. (that's silly talk...bar stool racing). The 850's weren't built to race 200 HP turbo sleds...they are light weight, quick, fun trail weapons...A heavier sled will beat you up, and wear you out on rough trails (this is were the 850s shine)
You'll never hear me bad mouth a yamaha engine...I don't care for Cat's build quality (fit and finish), and frankly I find yamaha to be uninterested in sleds at this point...they are just going to paint cats blue, and put stickers on them...if you like that ...cool...But I don't (as an old , longtime yamaha fan), I find it disturbing...so I will be riding ski doos. Yes I work for a ski doo dealer, ...but even if I didn't, I'd still ride ski doo at this point.