I've got about 80 hours on mine. As far as I know, it was one of the first ones delivered in Wisconsin. So far I've used it with the FEL, MMM, box blade, rear blade, middle buster, and tiller.
Only problem so far was a failed bracket that holds up the air cleaner assembly. Dealer replaced it with no questions. The assumption is that the original was faulty and probably cracked during stamping. I've also noticed that there is a noticeable amount of flex in the frame when approaching a slope diagonally, especially with the loader weighted down. Dealer says that it's to be expected since the frame is not boxed in, but I'm watching it carefully for sure.
I use the machine daily for cleaning up after two horses, as well as mowing four acres. I also have tilled about 1/4 acre of gardens so far. It was able to till through grass that had been untouched for years with no problems. Being a SCUT, I had to really shorten the tiller's PTO shaft though. It's a bit of a bugger to hook up, but runs like a champ once it's set up right.
The first job I used it for was to spread about 60 ton of crushed asphalt on our 200 yard driveway using a box blade. No problems at all with this. Being a SCUT, I was able to easily adjust the top link from the seat as needed.
I've swapped my rear wheels side-for-side and sit about 4" wider now. That, combined with having the rears filled with Rim Guard, makes for a very stable ride. I also have a 320 pound cement block that I attach to the 3ph when using the FEL for anything heavy.
As far as fuel use, I use about half as much mowing as I did with my old JD 318. That's the only comparison I can really make, but I think it does okay on the fuel use.
The R4 tires (even when in FWD) are not the best for traction, so I've got a set of chains for the rear. Haven't tried them out yet, but I hope they help this winter. The turfs just didn't seem strong enough for FEL work, and the R4s seemed like the best compromise.
Hope this helps. Feel free to ask any specific questions you have.