I only have 100 miles on mine, so far I really like it though. I made a fair amount of changes to it, to suit my riding style/conditions. 16" wide 2" Camo challenger track, mountain skis, bar riser, moutain, etc.
I chose the XTX over the MTX mainly because of the better tunnel, updated suspension with better shocks. Plus I was planning on a track swap with either sled anyway.
So far the tunnel works well in deep snow, with the running boards cleaning out pretty easy through the cut outs.
I havn't exprienced the rough rear skid that 7Rob1 has, however I have not been on any bad trials yet either. I hope it's not as bad as a 02 Viper with stock shocks. I had one, and it killed my back, untill got the shocks re-valved!
Still playing around with the suspension. There is alot of adjustability to it though, so I should be able to find the set-up I like.
It turns/handles very well. I think the tipped up rails also improve the reverse function, I was able to back up in soft snow for a long ways. Kind of suprised me how well it backed up and didn't get stuck!