Cat skids are lighter and WAY stronger than the stock RX skid. I have used and abused my Cats like you wouldn't believe, and I weigh 250+ lbs., and the only thing I ever did was blow a rear Fox shock. Actually, that was my friend riding it who did that, after holding the throttle pegged on my ZRT-800 coming up about a 100 foot, 50-60 degree slope (it was a wall in a sand pit, snow covered of couse). He launched off the top and flew so high I know he could have cleared a small house. Blew the shock, but the skid handled it without a problem. Thats on a sled close in weight to an RX. And yes, the rider was nuts...but we kept egging him on until he did it. Didn't take much...hes an awesome dirt bike rider, and took to sledding naturally.
I have to laugh at the differences in the way sleds are built for mountains vs. our trails. Those wheels would last about 1/2 mile here before being dented up by ice chunks, stones showing through, etc. I guess you don't have to worry about that though. Awesome looking setup!!!!!!!!!
Jim