Porpoise;
The Quick 36 mowers are single drive hydros, meaning they have a fixed displacement pump and a variable displacement hydraulic motor. The hydraulic motor then drives through an enclosed geartrain/differential (much like your car or truck) and then finally to both drive wheels.
The biggest benefit of a hydro (especially on a walk-behind product) is the ability to match the speed that you want to walk and also the ability to change directions instantly without clutching or shifting. If you have a lot of low-hanging shrubbery for example, the hydro allows you to pull in, back out, pull in... without all of the stopping, clutching, latching, shifting, unlatching, pulling, latching, shifting....etc. one has to put up with from a typical belt-drive mower. The hydro makes a HUGE difference, providing ease of use in real-world situations.
The Quick 36 does have limitations on hills over about 20 degrees because of the differential. But unless you're mowing flood retention dams or earthen retaining walls, it'll do just fine in the majority of situations. As a general rule with a few exceptions, if grass will grow on it, you can cut it with a Quick 36.
People who own our machines are almost always surprised at how easy it is to steer. It's true that you do have to steer it with the handles, but it requires very little effort. A couple of the reasons for this are the lightweight (75-175 lbs. lighter than competitive machines) and our very short length. Besides delivering a beautiful quality of cut, the 3-blade deck on the Quick 36 makes the mower 15-20" shorter front to rear. This gives the operator much better leverage over the machine and makes the front end go where you point it with very little "man-handling". To illustrate the point, we sold a machine last week to a lady landscaper who weighs 100 lbs soaking wet. She had shopped and studied commercial walk-behinds for six months and demo'd virtually every brand out there (spreadsheets were involved!). She ended up buying one of our Super-Duty mowers because she said it was the only 36" out there that she could comfortably handle.
Let me know if you have any other questions and we'll do our best to answer them.
quick36.com
Gary
Better/