The X540 should be more than enough for mowing 2.5 acres, BUT if you're willing to spend $7k on a garden tractor, why not drop another $5k and get the very best- the X748 :laughing: :thumbsup:.
Seriously though, the way I see it: the X748 is a lot better value than the X540, even with the nearly $5000 increase in price. I was just at the dealer this past weekend picking up a few parts and browsed the mowers on the showroom floor (and the new Gators).
Like Carl Bert just said, you really can't compare the 2 tractors. The X748 has the 3 cyl Yanmar diesel, 4wd, differential lock, and is nearly 50% heavier than the X540. I'm guessing the X748 will also keep a higher resale/trade-in value if you ever wish to get something else in the future.
It would really come down to the financing options if I was in the market for a new premium garden tractor. I believe I've recently read on TBN that some dealers are still offering 0% for 36 months- looking at it from that perspective, the X540 is $200 a month and the X748 would be $330 a month- well worth the extra cost in my opinion.
The X585 is another very good alternative if you're looking at something used.