I use Dixie Choppers, but the engine you mentioned would be the one I would get if I got another gas engine on a Chopper or the new Honda 24 HP sounds mighty good too. From what my dealer says, the 23 Kohler is as powerful as a 25 Kohler, but holds up much better. It is supposed to be as reliable as the 22 HP Kohler, which I have on one of my Choppers.
I would go with the Exmark Lazer 60" Toros has not caught up yet in the ZTR mowers, in fact they bought Exmark , so they could take the Exmark Lazer and put Toro on it and then they added the Toro deck.
I'm not at all very trusting in Toro, they sold me a Z Master 325 and would not stand behind it at all. They would not even trade me out of it, by far it was the biggest piece of junk they've made so far.
The Toro ZTR do look great, but you well not like the service, compared to Exmark. Compare both mowers before you decide.
i took out a toro for a day and it had the 23 kohler on it, it was a fairly good machine but i still amd totally devoted to dixie. The hydro dampening system on all the other ZTR's just piss me off, i didnt like it from the first time i put one on my trailer.
I agree on the steering dampeners on these other brands. I've tried them out too and some are so hard to push, it's like your pushing the mower across the lawn. DC's new VTC machines don't even have the little springs they used to have. Talk about easy to operate, DC's are the easiest mowers I have operated ever.