For this season, we replaced our worn-out Toro ZTR with a John Deere 997 diesel ZTR with rear discharge. Because we were buying a new mower, we put together our list of requirements: diesel engine; rear discharge; hydraulic deck lift and no foot controls.
Only John Deere had a mower that met all of those requirements (Kubota came close, but their diesel rear discharge unit had a foot control for the deck lift).
We had to special order it from our dealer because of the rear discharge which isn't popular with groundskeepers, lawn maintenance and other commercial users. We needed the rear discharge because we grow christmas trees and the side discharge mowers load the seedlings up with clippings and stunt their growth. And, as it turned out, only John Deere had a machine that met all of our requirements.
Overall, the mower works great and does a nice job around our farm. It is easy to use and operates well -- it has the "feel" of an expensive, well-made and solid piece of equipment. Which is good, because it *is* an expensive piece of equipment!
A commercial user would probably not want the rear discharge as it leaves clippings in clumps. Otherwise, it is a powerful cutter that doesn't even notice the thick grass areas that use to slow down the old Toro. As heavy as it is (with the diesel hanging off the back) you'd think it would have better traction. We may switch to more aggressive ag-type tires to get a better grip.
The operating controls are well thought out and placed nicely. No foot controls make it possible for a paraplegic to operate it with no modifications (important to us) other than getting on or off the machine unaided. The thumb-operated hydraulic deck hoist is a very nice feature as is the PTO cut-off switch. The diesel is the same Yanmar-built engine JD uses in the diesel Gators and other smaller products and is a well-made, good-running piece of gear.
The only problems we've encountered this year are that the seat is not comfortable on rough terrain (forcing us to slow way down), and the machine is fussy about it's cooling -- in hot, dry conditions, you have to really keep the dust and clippings out of the radiators or it overheats a little and automatically cuts off the PTO.
Not hard to clean but it does require lifting the engine cover all the way off (again, not hard to do -- JD brilliantly engineered how the engine cover attaches so you don't need to do anything except open it and lift) and thoroughly blow the radiators clean every time you use it.
Overall, we are very pleased with the machine and we're glad we spent the big bucks to get exactly what we needed for our operation. We hope to be using it for a very long time.
Some 997 operators will say that getting a rear guard to protect the engine cover is necessary. That has not been our experience. Out in the tree rows, we turn around carefully so we have no issues (yet) with the engine cover smacking anything.