Dixie has the fastest mower no doubt. But they get it by running hydro pumps with higher GPM capacities than the Wheel motors are rated for. We replace many wheel motors and hydro pumps on Dixie Choppers at work. Hate to see the damn thing come in. You can figure a $1000 bill when one goes bad. You know its bad when at a service meeting the company guy says "you will have pump failures". Also dixies run the blade tip speed too fast and larger ones have no saftey start for the deck enguagement. Cities cannot buy them because they do not meet OSHA specs for mowers.

Both Ferris and Hustler offer models with the CAT engine. Technically the engine is built by ISM the same company that makes NH compact tractors, the engines are sold by a joint venture to Perkins. Since Perkins is owned by CAT, they just paint them yellow and put a big CAT decal on them. Look at the tag on the injection pump and you will see ISM and Perkins names on it. Good motor.

If I were looking at a ZTR and not wanting to go to a diesel then personally I would get the EFI Kohler engines. Also stay away from anything with a Generac engine on it.