I have had really good luck with Husqvarna products, I bought an Ariens HST for my mother back in 2010 from HD and it's going very strong.
I personally have a Husqvarna older GT 24hp with 54in deck, it cuts great.


Husqvarna makes lawn tractors for many companies and I like them a lot, the steering gears have a zerks as well as the outer hubs, inner spindles on the front suspension and all the spindles on the deck has a grease zerk, the Ariens has 7 zerks being it's a 2 blade and mine has 8 with 3 deck blades.
Also I just bought a new set of blades for my husky off Amazon for $32 delivered to my front door and there made in the USA. The Ariens has lifetime blades, they send my mother a new set of blades every two years and I throw them on, usually by that time the blades aren't worth sharpening, she sucks up a lot of rocks and sticks down there.
For an acre I would look at something like that Ariens, I'm a fan of the Kholer over the B&S like what's in my GT but there both decent.
Absolutely stay away from a MTD made mower, it won't last under the best conditions, and stay away from the D line of JD, if you buy green make sure it has a X in front of its name x300-x700.