It strikes me that riding would have to be better than walking or even riding on a sulky behind a powerfull walk behind. I have no knowledge of a Q-36, but there are many good commercial walkbehinds that would also work.

If tight spaces and manuverability are the issue, the walkbehind would probably be best, as they will go into areas that most ZTRs are just too big for.

If that is not the issue, then take a good look at a small ZTR that is super manuverable, and a small one can be had for just a little more than a consumer grade.

I am not sure, but I read so many of these posts that are concerned with the dollars, but fail to take into account the over all long term cost of ownership, how long the unit will give good service. I spent $7000 and got a machine that will last me 20-30 years, or spend $3000 and get one that will last 5-10 years.

Here is a link to one that will last a long time and will be a pleasure to use too.

Here is a link that might be useful: Several different models to choose from.

The Quick 36 uses a lawn tractor hydrostatic transaxle.
Unlike the commercial mowers that use separate
right and left brake levers to do the steering, I think you just push sideways on the handle bars to turn it. The differential in the transaxle lets the drive wheel on the inside of the turn move more slowly than the other drive wheel. Without the weight of the driver to haul around, the
lawn tractor transaxle should last like a commercial unit should.

I've never seen one but the company has been in business for
years and they sell a lot of models.

I'm also interested in buying, (or building), a commercial walk-behind. Manual and hydro lawn tractor transaxles are a dime a dozen and it would be easy to build a walk-behind drive train around one. What concerns me about using a tractor transaxle with a differential, (like the Quick 36), is that in addition to having to steer the machine using more manual effort, keeping the deck going straight on a sidehill would also be much harder.

(One of the reasons I want a commercial walk-behind is to mow my ditches. I'm currently doing it with a good ol' push mower and it's getting old.) ;-)

Without the individual wheel drive/braking other commercial walk-behinds have, I envision the Quick 36 deck wanting to head downhill as I'm mowing parallel along the slope. With other commercial walk-behinds, I could either speed up the drive wheel on the downhill side, and/or brake the wheel on the uphill side to keep the caster-supported front of the deck from always wanting to roll downhill.

The Quick 36 looks intriguing, but I don't think it would work that well for my application. They made the wheelbase very short to make it easier to muscle around turns out in the flat, but I'd like to see a video of one being used on a slope.....

You wouldn't want to use a q36 across a sidehill. Its very maneuverable, but not good if you have to maintain direction across a slope, it would turn downhill like you mentioned. You'd need a dual-hydrostatic walk behind.

Get one of each brought out to your house and try them out. You will find the answer to you question first hand. If the dealer won't do it. Look elsewhere.