I actually don't own a Ferris it is a Derby which is a ferris painted green and sold for less because it is a homeowners model. I campaired mine with a ferris before I baught it and there was not a single difference in the strudyness of the machine. It is a hydro but it does not have independent wheel motors. On each handle bar there is a thumb control push it forward for forward and you guessed it back to go into reverse. Although it uses disk breaks to turn it still turns better than a belt drive because you have the instant reverse and the speed is controlled with your thumbs. What makes me nervouse about all the other mowers out there is I spend a lot of time on steep hills, with my Derby I can control the speed instantly and never have to take my hands off the machine. I understand that you can slow the machine down with the hand controls on the new ones but the part I am thinking about is when I have to turn back on the hill. With my current mower I get to where I have to turn come to a complete stop then I can lock up the upper tire and pivit the machine around for the next pass. With the dual drive hydros they way I understand it you can't really "lock up" the upper tire. You can stop the tire but if you squeeze to hard it is going into reverse not hard enough and it is going to go forward. Forward isn't so bad, but I am picturing being in the middle of the turn where the mower is directly up hill from you and squezing that lever to hard and having it come back on you.
I guess my question is why the heck don't they use the thumb controls on the dual drive hydros? The only thing I can imagine is that your thumbs get tired and you will get blisters the first week you use it but once the muscels in you thumbs that you never use get toughened up a bit you are fine. And tracking would take a while to get used to, It would run just like a ZTR, get a fixed sulkie with caster wheels and you got a ZTR.