I broke my Anti-Sway bar last year just before my last trip of the season, I did notice the handling was off slightly on the Saturday the prior to my trip (no time to fix it prior too) and was surprised when I found the bar snapped. On Sunday morning I dialed up the front springs 3 or 4 (I have it written down but not on me) full turns. Rode it hard in the trails, both tight and fast stuff and was really amazed at how well the machine actually worked. I am going to replace the anti-sway bar as I get to do a lot of high speed trail riding (not really that much ditch banging or a lot of jumping) and you can notice it just a bit but it's not really that bad up to 90-95mph, under these speeds with higher spring loads it was surprisingly good. At high speeds you will feel it set (not boat, boat would be too extreme of a word to use for this action), onto the outside ski plant it and hold the set through both rough and groomed trail. With the Anti-Sway bar it just doesn't have that sensation of planting the outside ski. I have a tricked out MXZ 670HO with alot of after market suspenion under it, including a Fast BLT kit up front and a custom made Anti-Sway bar assembly with a much stiffer bar used. The machine boated (more then I liked) when the BLT went on and after trying a lot of different suggestions, my buddy and I fabercated up the new assembly with a well used Mach Z bar, I ended up snapping the Anti Sway bar near the end of the 2002 season, I can tell you that the Machine was pretty much uncontrollable to drive, it would dive hard and never stay planted on the outside ski, it was pretty much Scary to drive.
The ProX2 and I could hardly notice it, I'm aware that there are some differnces in suspension between the X and X2, but thought I would let you know how it worked out (even though I didn't want it) for me. I was surprised at how little of difference it made, I drove it for another 800miles on my trip with out the Anti-Sway Bar with no problems or disappointments it worked well.
Good Luck,