Walker builds an amazing zero turn machine. The grass pickup system has an additional metal bladed fan to really suck up the clippings. Stands the grass up and gives you a clean cut. Also works well on leaves. I once drive mine thru 3' tall grass and it shoots a 20' roostertail out the back. Impressive machines.
I really wanted to buy one after checking them out but I couldn't justify it to myself for the extra coin over the conventional zero turns for my limited use. If I was a commercial guy, I would definitely have one in my fleet for picky customers with trophy lawns.