Our area sewer utility had a special deal going for customers who wanted a new toilet. When I checked into the program, 2 of the three models they offered were discontinued and the ratings for them were only fair. The other one was decent but was out of stock.
I replaced one toilet in my house with an American Standard Champion 4 that I got from Lowe's for $239. Had really high ratings from consumer magazines and included everything needed for installation. The ad I saw sait it would flush a bucket of golf *****. Unfortunately when I got it home and installed it, I found a small crack in the tank. I only noticed it because of a 3" water spot on the floor.
I called A-S and they immediately arranged for a replacement tank at no charge. When I got the tank 2 days later, it also included all of the internal hardware and they didn't want the old tank back so I wound up with freebie spare parts. Other than that, it seems to work like a toilet should.
I don't have a brand preference, but after installing 6 new toilets in our rental purchases, I have to recommend the one piece setups. So much easier to keep clean, although being one piece is heavy, and if you do break it, the whole thing is toast, but I don't see too many getting broken.
No need to spend anywhere near $500, but stay away from the $150 ones though, they are...well, crap.
I remodeled a bathroom two yrs. ago and put one in. Love how it is a little taller than the old one.
I put a Toto in another bath approx. 8 yrs. ago and it has been flawless.
You won't go wrong with either one.