As will be said a lot in the posts to follow, base your choice on how you feel about the dealership and the parts/service people who will be providing the maintainence stuff you'll need first. Then look at which tractor seems to fit you and your wife best -- the seats and controls all function well, but some seem made for people of different physiques than others. Then look at price of the tractor and also of commonly needed items like filters and such.
I looked hard at Mahindra, Kubota, NH, JD, Agco, and Case. It came down to Case vs. Mahindra and I swung toward Case. A big factor was the adjustable suspension seat and steering wheel on my DX over the Mahindra seat and fixed wheel. Another was the apparent strength of the steel in the bucket. The Mahindra guy was great, but he was a one man shop with no service department to speak of while the Case dealer was/is a 3 generation family business that moves a lot of equipment for 3 different brands, including Kubota. I ruled out Kubota despite owning one at the time and loving it because the seats just didn't feel good -- it seemed like I was sliding off when the thing was just sitting still and I have hilly ground -- and the controls didn't fall as easily to my hand/arm/foot/leg configuration as on the Case.
They're both good machines. You will quickly adapt to whichever one you get. Kubota has been around longer, but most of here would be surprized if Mahindra was not here to stay. You will age some and get kind of creaky as the years pass. Which one will work best then? It's a tough choice, so take your time and drive both of them, preferably back to back. See if either dealer will bring one out to your place for a test run on your ground. Ask around the community and look to see what other people are using.
