SCAG invented the commercial zero turn. Been in it the longest. They were morphed out of a metal fab shop. Every bend, every connection is pure art that can only come from experience. Very few welds. I looked a lot of places before settling on a SCAG. They are of high opinion of the commercial guys as well. Really though, mower performance is first about the deck design, not the engine. SCAG's deck is built like a tank and designed like a jet engine.
I needed mower that could mow anything and not stop. I was tired of "lawn tractors" as I was constantly changing belts and parts. They just aren't heavy duty. So I went looking and I found the SCAG company. All steel, all USA made, and powers through cutting like an ox. Super simple design makes for less issues and everything is easily accessible for repair. My guess is most mower companies have copied SCAG's designs as they all look a lot alike. Now, everybody is in the zero turn game. I would not even consider buying a commercial mower from a tractor company, kubota, deere, or otherwise. The name doesn't mean a thing in mowers because thats not their thing. Stick with a company that has experience in building tough mowers for buying mowers. Buy your tractor from a tractor company and your mower from a mower company. Thats my 2 cents but its is MY 2 cents. You can spend yours how you want but don't be disappointed.
One success story. I mowed a 5 acre abandoned horse farm that had 36" high tough, thick field grass that hadn't been touched in about 2 mowing seasons with my SCAG. The SCAG never got tired, just dusty. This is not uncommon for me to have to mow high, tough grass like this, just the size was uncommon. It mows it everytime. Its a beast.
Bottom line is this: If you want the best built mower that lasts and can cut almost anything your bush hog can then get the SCAG. Don't buy it because you are price shopping.
PS: I wanted a Cheetah but they didn't make it in 48". I wanted the smaller size for getting through backyard gates and manuvering around obstacles in tight places so I went with the Tiger Cat. The only real difference I saw was the independent seat suspension...and the price.