Look at all mowers available very closely in the shop, read the literature and the comments/experience of those on this board and narrow the field to your top choices, then TEST DRIVE/CUT. Preferable do this side by side or within a very short time period of each other on the same site. If you're willing to spend upwards of 9 or 10,000 dollars the dealers need to be willing to bring them to you for a try.
I intend to post a more complete report but I'll just say that I narrowed my choice to the 60" 27LC Scag TT and Exmark Lazer Z. I cut half of a 1 acre lawn with the Scag and an hour later the other half with the Lazer. I bought the Lazer. Will