bobcat and scag (the cougar I think) made something that LOOKED like a walker...but these had to be very different than the walker at the time, because of patents that were still valid. They did not do well because they were almost twice as expensive as their own companies other mowers and nothing actually like the walker. They did not have removable decks and couldnt take other attachments, Certain walker patents have since expired, bringing about the Navigator. the navigator is 150% a better mower than walker, many improvements. However walker is still over all better because of the implements and support and after market toys etc... over all more versatile better machine. But Navigator is the better mower... IF you JUST need a GHS style bagging mower. Get a Navigator. if you want it to do everything maintenance grasshopper and walker are still kings.