I have had good luck with the upgrade.
I did all 3 upgrades essentially at once on my 2009 XP 154 and very happy with the results.
- T-Motion
- S-36
- 2010 skid shock
I agree with the comment above that all 3 seem to play well together.
I am 240 and my kids are 160'ish and I wanted it to be easier for them to ride.
The difference is like night and day IMHO.
It isn't quite the same as my XM, but the sled is much easier to ride, more nimble, and frankly feels less like a tank than it used too.
My kids find it much easier to ride now. I almost don't mind swapping them every now and then
Plan on it taking some time and search the web for all the tricks to dismantle and re-install the various parts. A few of the articles I read saved the day !!! The instructions aren't too bad, but they leave you hanging in a few critical places if you haven't done it before. (like me)
An electric impact driver will save your life on all the cross members in the skid!
Don't toss your old skid hardware if you have a 2008 or 2009, the 2010 shock upgrade kit I bought didn't work with the T-motion kit because the new mounting rod was too short, so I had to use the original 2009 mounting rod to mount the 2010 shock kit to the side rails. Lucky break that I threw them in a bucket and didn't toss them! The new cross member is a better design, but if I remember right it was to short because of the way it mounted on the new T-motion rails (my kit was designed to go in the original 2009 rails)
Also, the S-36 kit requires the bushings be pressed in. I had to take it to the dealer for that. I found that to be annoying and costly !!!