Lot's of good comments here, but looking at what you are mowing (those 7 questions) is the best advice. I have a 60 acre farm that I have lived on 14 years now. I "finish" mow 5-6 acres with my mower, although occasionally some is done with the bush hog. I first bought a Craftsman 42" rider, then a Deere 48" rider, and now have a Hustler 60" ZTR. A few truths about mowers...
1) most are pretty good. The difference is how they hold up in the long run. Part of what I learned is that rough terrain and constant use take their toll on cheaper mowers. Where they save money is using lighter weight parts. Steering linkages, shifters, wheel axels, etc. After 4 years, my craftsman was falling apart, engine was fine, but by year six it was worthless other than the engine. Somewhat the same for the Deere, which was bought from a dealer, not a stripped down version, and it was not worthless, but you could see the years in it. Bottom line, size the mower to the job or you will pay more as you replace them more often.
2) when you get to the professional grade mowers (hustler, deere, exmark, toro, etc usually 6k-8k) people are fanatical about their brands. In general, they are not that different, but what is different is service. How close is the local dealer and how good are they? I like scags, but their dealer network is weak in this part of the country, and parts have to be ordered. So the dealer service network can make or break your experience. Some go ballistic over this idea, but those who really know will tell you the dealer is much more important than the mower.
3) look at what you mow. Big decks are nice, but can scalp, do you want to collect your clippings, are there narrow places you want to get, etc. if your lawn is a big flat field, get a wide flat deck and a speedy more and you will be done in an hour or two. Otherwise, think about mowing time v weed eating or push mowing.
Good luck.
