Just another thought: The hydrosatatic is easier to drive, and leaves the hands free, but it does seem to use some of the available power as a trade off for convenience. I've got a Century 3647 with the shuttle shift, and don't mind shifting. Once you drop the clutch, you're in. Direct power transfer to the wheels.
My neighbor has a JD with hydro, and more than once he's said that he wished he hadn't gone with it. It does sound like an electric tractor to me, and I've seen him trying to load dirt with the FEL and the tractor just hums and sits there.
I don't know for sure how much of the power is routed to provide the ease of the hydro, but it must be some.
That may not be important, but when you're wishing for that last little bit of hp, it sure can seem that way.
anthony