I just put one on my Mountain Max last week. Before, on ungroomed trails, with very frequent, nasty moglus, it beat the tar out of me when the coupling engaged. Works much better on this now, can carry much more speed. I haven't noticed a difference on more open trails. It does lift the skis much more off the line, and as of right now, I'm not sure how well I like it on climbing. I think I just need to get it dialed in and get used to it, I'm new to mountain riding.
I ride with 2 more experienced riders that have put it in, they love it. Looks like the front limiter wants to be cranked up pretty tight.