SCMCG,
Also the spindles are upgraded to cast iron versus aluminum and the engine to the B & S Endurance Commercial 28hp/810cc versus the Kohler Courage 25hp/725cc as well as the 12" rear drive wheels versus the 10". All in all, very well worth $800 for the upgrades you mentioned and I mentioned(plys rated as Commercial versus Residential). It's your money I'm just teeling you my perspective(and I lean towards entry-level Commercial ZTR's. When you get into the $5500-$6000 price range thaere are a whole bunch of solid machines that will most likely last you a lifetime if maintained. When I'm spending several thousand dollars, personally I don't want something that will be giving me problems 5-10 years down the road. Below is a link where you can compare the two Husqvarna's side-by-side.
Zero Turn Mowers - Comparison Chart | Husqvarna
Ok I see now. After talking with a commercial guy I know, the aluminum spindles don't scare me at all with my usage. Also, while I do like the Kawasaki engines, I am pretty confident that with excellent maintenance, any of these engines will do me just fine. My wife is really putting the crunch on me on this deal, so $800 savings would be substantial should I feel like the MZ5220 would serve me well enough. If it weren't for the dinky caster wheels/tires on the new Kubota, I would most likely go that route just simply due to the 4 yr warranty on the whole machine. But I think those small wheels will be extremely rough riding on my yard as my ather-in-law has a home depot cub cadet ZT and it is a very rough ride. While I don't want to settle, I also don't want to spend any more than is necessary right now I guess.