I have had 4 different alphas. Every years except the 23, everything from stock to a turbo and everything inbetween and now have a 24 600 catalyst. I will admit on the spring or icey snow on a super steep slope the twin rail was a little better than the alpha on the Ascender. Not near what the interwebs would want you to beleive though. I can say with 100% certainty that the Catalyst is far better than any of them including the twin rails in every conditions. It will sidehill with ANY sled out there in any condition. It is as stable as a twin rail going down the trail. It is so much lighter it just does what you want with less effort than any sled I've ever rode. I still have 3 800 alphas, a 21 turbo alpha, a 22 bone stock, and a 21 with a "little bit" of motor work and its not even a thought when I go riding which sled I will ride. I will ride the bone stock 600 because it is that much more fun, that much more predictable, and will hold a side hill better than my 2018 twin rail would. If you haven't thrown a leg over the catalyst you need to because it is that good and I'm not easy to impress. The fit and finish on the Catalyst is also the best Arctic Cat I have ever owned. I cant imagine fuel being an issue unless you have to ride 30 miles each way on the trail, which i dont so gas really isnt an issue for me. The gas gauges on Cats have been notoriously off in the past too but it seems much closer to correct on the Catalyst. Saturday my gauge was a little above half and I put 4.5 gallons in it. My only complaint on the Catalyst is that the gauge is terrible. It gets condensation under it a mile from the truck each time. This is true for all 4 of them that are in my riding group. The sled really is amazing. I havent had so much fun snowmobiling in a long time and I'm on a stock 600 when I have pretty much anything I want to choose from in my trailer.