I've read several horror stories on Tractorbynet in the kubota forums of kubota owners balking at the price of SuperUDT, and going with a -equivelent- that's ended up with a ruined tractor and a big bill. Get off the dime and spend the money on the SuperUDT and have some piece of mind.
The hydrostatic transmissions on the Kubota's are all pretty winey and noisy. On hills, make sure that your throttle is high and your in a lower gear range. If you stay in high, then be light on the go peddle.