Ric, slow progress is still progress; I offer to you that when you operate a zt in the required manner so as to avoid turf damage that in the end, a quality tractor will mow in a time so close so as to make it virtually a draw.
Tractor one, zero turn, well- zero.
robert as I said previous knowing how to operate a zero can make all the difference in the world. I've been mowing with a ZTR's and Tractor's for a long time, some thirty or more years with Dixie Chopper, John Deere, Cub Cadet, Honda and so on.
In the time, 24 years I worked for the county the idiots at the county office discovered Lawn and garden tractors in the real world of time and money don't cut it. I also started my business in 2006 with a lawn tractor and shortly found out it wasn't the way to go and replaced them with ZTR's.
If your tractors are so great and faster than and cut better than a ZTR explain to me why myself and all the Professionals in the Lawn-Care business aren't using them? The answer is time is money and the only way you make time and money is with a faster cutting mower, the ZTR.
Now I agree with you as far as making a zero turn on turf without doing damage but I also know that anyone with any common sense knows you don't operate a zero turn that way if you want to stay in business, that was not the design or intention of a ztr.
You talk about mowing speeds 8 and 10 mph, again any idiot knows you can't mow that fast and get a decent cut, those speeds are for transport only, so if you mow the correct speed for your tractor the ztr will be faster and you talk about mowing slopes and as of yet I've not seen anyone talk about slope mowing and doing that the right or correct way.
When it comes right down to it this whole discussion really is irrelevant because you're talking about two different mower designs. The ZTR is the best of the best for what it was designed for and that's mowing lawns and saving time and you cannot dispute that, just like the tractor and its design intention.
I offer to you that when anyone that knows how operate a ztr in the required manner so as to avoid turf damage that in the end, a quality tractor will not come close to the speed of a ZTR. I think if you stop and think about you would realize that there is no way possible you can make a three point turn or 180 degree turn on a tractor as fast as a ZTR, again common sense would tell you that, so time wise the ZTR would finish long before the tractor.