I have a Kuhn EL35 (52") on my JD 750. Just covers the tire tracks in the dirt, which is a good thing.
I don't have hydrostat, but I just use 1st gear in low range and run the engine up to the PTO max. The Kuhn will go about 10" deep, so giving it plenty of PTO power and going SLOW is important.
I also have clay below my topsoil, and plenty of Rhode Island rocks mixed in. The tiller breezes thru it like nothing. I have set the slip clutch so that it slips if it hits a big rock and thus will not damage the tiller. I just ripped up a piece of ground that was nothing but a bull briar patch. Ripped up the briar roots and stones like nothing at all. Going to put in strawberries next year.
I don't know if other guys on TBN do this, but I put all leaves and clippings on the garden and grind it all in with the tiller. No need to compost or put the leaves thru a shredder. The tiller just puts them under and they rot fast.
I know that I am rambling on here, but one more thing: I use the rear tiller all the time to loosen up ground so I can scoop it up easier with my FEL. I reshaped the banks on a road that runs down the side of my land and used the tiller to loosen everything up before attacking it with my FEL. Loosens the dirt up fine and the FEL can then move it and shape it better.
Good luck with your tiller! You'll wonder how you ever lived without one.