Well we have one - bought it in November. So far we've only used it to move a few snowbanks around, so it's not had a chance to do what we want it to do - which is hay about 20 acres. (oh, and drag the riding ring it does that nicely too.)
It's pretty easy to handle, the loader knob is pretty sensitive but we're all learning which way means up/down.
Started up last weekend with a little assistance from the space heater after not being run for 3 weeks and the temperature was 10 below.
Very stable on the hills, and once we got the tires loaded we really haven't needed the 4wd much.
When I tried it on the lot I also tried the 1455 - the 451 made the "little" tractor feel like a lawnmower.