The TN has a very nice cab as does the TDD. The TL has a bigger and nicer cab then the other two (well, not so much bigger compared to the TDD but nicer).
However, if you want a great cab then buy the TS-A (T6000 now) and drive home happy. They smallest TS-A/T6000 is 80 pto hp but they are by far the best cab on the market in that class and once you sit down inside one you will not want to leave. The cab is so comfortable and, well, basically it's beautiful. It is my dream tractor as it is the perfect size for my main tillage and hay tractor.
The TS-A cab has so much room you really do feel comfortable in it. The doors are rear hinged which allows the entire side to be obstruction free as well as making it easy to get in and out. You can even get the sky light if you plan on doing a lot of loader work or if you just want the sky light (it has a screen to close it off if you don't want the sun shining in during field work.
The TL-A cab (I think these are now T5000's) was nice but I felt like it was too short for me and my sitting position. I could never get comfortable with the ceiling sloping down in front as much as it did on a fairly short cab anyway. So far I have been the only one to complain about that as everyone else loves the room in it.
The TD-D has a more basic cab but is very roomy and gives you good sight lines with an solid tractor underneath. I have looked at this model as it is at a real nice price point with nice features for the cost. The TD-D has the exhaust pipe in the view of the operator so you might want to see if there is a low exhaust kit for it if you choose this model.
I have spent the most time in the cab of an old Ford 7710-II but after that comes the cab on the TN. The TN cab is real spacious for that size tractor so you feel comfortable. The AC will freeze you out of there and I had to adjust it some so that I quit freezing the front window. If you go with the TN get the low exhaust kit so that the exhaust pipe isn't sticking up in front of the front window. Maybe NH will or did change this but the last I knew they didn't. The exhaust pipe isn't overly big but is there and you find yourself trying to see thru it from time to time. Other then that this is a nice cab.
New Holland knows farmers spend a lot of time on these tractors so they have been trying to build and design cabs to make them as useful and comfortable for the farmer as possible.
I do not know what dealers are in North Carolina though so look around and possibly see which farms run blue and ask them about the local dealers.
I am curious, if the Kubota didn't give you problems why change?