I was able to ride the 858 sleds a week ago. Our Cat rep met a group of us up Logan canyon. We were able to ride them for about 2 hours. We rode a 165" mountain cat, 165" sno pro and a 154" mountain cat. They all had the 3" tracks, the rep told us that the machines were from the original media ride in west Yellowstone and had been re flashed about 40 times. The engineers are busy making fuel and clutching changes before production starts. I was excited to ride the sleds in the conditions and area we know pretty well. The trail had been groomed recently and the corners had some bumps. The sno pro was very smooth down the trail, my personal sled is a 2019 154 Alpha. I never could dream about hitting the corners as fast as I was. The catalyst is planted in the corners, and feels like a dual rail hitting the bumps on the straights. The 165" tack was smooth over the bumps where in the past I have felt the slap of the longer rail. The whole time climbing we never switched the shocks from #1. I was able to ride the 600 sleds last spring in island park with Cat. The 858 is not as light feeling on the snow. We had 2 600's with us a 3" and 2.6 154. Everyone that rode the 858 said the same thing, it felt heavier. The 600 is almost too easy to ride in the trees. I find my self riding wrong foot forward not because it needs it to side hill, its to keep me from over compensating. The 858 you can ride neutral and just look and lean your weight. The power feels great in all ranges, I felt like the bottom end is awesome, but hopefully will be better in the fall. You can defiantly feel the longer legs of the engine compared to the 800. The 858 is going to give any na sled a run for there money next year. I know snowest does not think so, but I'm pretty positive it will beat a 9R. Excited for next season