Is Deere overrated? No.
Are they overpriced? Sometimes yes, sometimes no.
It all depends upon what your uses for the tractor are. Deere offers a complete line of farm equipment, it dwarfs kubota in it's size. Kubota made their name in compact tractors and they make great ones, but a 35 hp CUT doesn't do much good for a row crop farmer. Most guys on this board look at things from a CUT owners perspective, mow the grass, move a few rocks, till a garden, etc. None of which takes equipment that is geared toward the commercial end of the market. You'll see very few kubota's on a real farm, even though kubota makes great tractors. They just aren't in the market to make what a full time commercial farmer needs. Same with kioti, mahindra, and pretty much everyone except Deere, Agco, and CaseNH.
If I were in the market for a CUT then Deere might not be my first choice. When I bought my MF 471 a few years ago I looked at all the other major brands and decided that in the 70 HP range that MF had what I was looking for. The Kubota
M7040 was nice, but physically much smaller than the massey with less all around capacity, the only thing equivalent was the HP, and the kubota was priced about $1500 more. The deere was similar in that it was priced higher but not quite as big and capable. Both the kubota and Deere had more bells and whistles, which I specifically DID NOT want because I was looking for a tractor that would still be running 40 years from now, I didn't want fancy electronics.
If I were a full time farmer who depended upon his equipment for his living then Deere would go to the top of the list. Deere's parts support is second to none and that extra $$$ for the green paint is well spent when you have a crop to get in and your off brand tractor is down waiting for parts to arrive from India. What farmers are paying for when they buy Deere is the peace of mind of knowing that if their equipment breaks then it will be fixed ASAP. It's the same reason that heavy equipment guys pay so much for caterpillar, it's not that the machines are that much better (though they're very good), it's that if they have a breakage they'll be back running in a matter of hours, not days or weeks. As noted by a previous poster, Deere is making big inroads in construction equipment because they have the same philosophy, a philosophy brought over from their farm equipment side.
Deere tractors are very good solid tractors. Maybe not that much better than the competition, but supply network IS much better than a lot of other brands and that's why the guys that rely upon their tractors for their living spend the extra money for Deere.