Being a dyed-in-the-wool John Deere guy, I've only owned a few other mowers over the years. I mow about 4-5 acres a week, so it's got to be a good mower. You've gotten some good advice. Stay away from el cheapo mowers, you'll never know the grief you've saved yourself.Of the more "budget" priced mowers, I'd go with Husqvarna. I had a 2010 27hp Briggs tractor with a fabbed mower deck. My neighbor, who is not real mechanical bought it and it threw a belt, it's a long story, not worth telling, but i bought it, put the "correct" pulley on it and never had a single problem with it mowing all day long for two or three years. When I got a chance to buy a really nice John Deere 425, I jumped on it and sold the Husqy to a local church which is still using it, I assume with no issues.
It all depends on your lawn, and how much you mow. If your lawn is flat, and small, almost anything will work, even an MTD. It's when they get hilly, and large that you need to look for more build quality. It amazes me that folks will buy a 5 acre piece of land that's hilly and try to mow it with a 12hp MTD that cost $750-1200 new and can't understand why the hydro didn't hold up. Those cheap hydros are fine for flat landers, but for us hill people, you gotta have something tough to mow all day in hot weather on hills.