I've had the 336D for over a year and it's been a great tractor. The clutch was stuck when I bought it, but it freed after I sprayed brake cleaner in an access hole in the transmission housing, and drove it around for a few days. It's a solid and reliable machine.
I've used it to move soil and gravel, move snow, pull trees, and bush hog. It does leak from the front hubs, but I filled the front axle with Lucas hub oil, and the leak is now very slow. I just need to top it up 3 or 4 times a year.