Different units, the FasTrak uses a single drive unit called a IZT made by Hydro Gear.
I suggest you look at the Hustler Mini Z, this unit uses the dual pump and wheel motor's (Hydro Gear pumps and Ross or White wheel motors) and is a true commercial featured unit, made for everyday mowing.
I would suggest a dual pump and wheel motor unit due to your hilly 2 acres.
The 19/52 Mini Z (Kawasaki engine) has a promo price of 5995.00 until the end of May.
The Hustler will have more features also, std deck lift, std cup holder's, large 23" tires, 12 gallons of fuel on board, and a better handling unit on hills or slopes.
1 thing to consider also......the Exmark product is sold to you by the dealer, just as the Hustler, the Hustler distributor for NY is right here in Syracuse, (I live here also) the Exmark distributor for Ny is in Lancaster NH, so if in a odd emergency parts need you have closer support, and it keeps your $$ local to the CNY / WNY economy.
Pj