I wouldn't bother with the extra 10. It will have more transfer but I don't think it will make that much of difference. My brother bought an XCR last year with an extra 10 for nostalgia and commented on how it didn't ride to bad until he hopped back on his edge chasis and said it is night and day. I would look for an edge skid or the ski doo sc3 also seems to be a popular upgrade on the site. I put the edge skid in my viper last year and wasn't impressed until I got it dialed in properly and now I am very happy with it. There is also a nice M10 for sale in the classifieds and I beleive another guy has the mounting kit for it in the classifieds as well. I found my edge skid on craigslist for $200 but by the time I replaced all the bearings, limiter straps, slides, rebuilt the shocks, and had it powder coated I had $800 into it.