I have had one of the first TN 65's sold here in my area. It is a MFWD with 32LA loader and 8x8 shuttle tranny. The tractor is great and I have never had a problem with the motor. The original tractors had some problems with linkage parts siezing up but NH pulled all the tractors in that were affected and tore everything down and fixed it. I have not had a problem since with the linkage. I have had other minor problems but NH has been great and my dealer has been exceptional and will do whatever is required to make right with any products I purchase thru them.
For what you are looking at, a 2wd TN 65 should be able to handle a 10' disc but if the ground is really wet, don't try it. If I were you I would look for a 8' transport disc as the tractor would be much happier. I run a 12' and can pull it in 2wd in mid summer when the ground is dry but going up an incline really makes the tractor work. Even with MFWD the tractor has to struggle to get thru wet spots and I do have to raise the disc from time to time. I am looking for a 10' and a 8' disc since I need a 8' disc to get into our pens. If I find a 10' I will probably sell off the 12 or park it till I might need it again. Brush chopping the tractor is great, I only run a 6' Woods because of working around all our fences and post. I do not want anything sticking past the rear wheels that can catch the wire or a stray post and cause me problems. The tractor can handle a 7' easy and depending what and how often you mow you can use a 10' chopper. The tractor will pull just about everything you can ask of it and you will be happy with it. THe price is in line for the tractor you described. MFWD adds about $5k the loader another $5k.
As for comparing to the JD 5000 series, I have heard people complain just as much about the 5000 series as I here them talk about the TN's. The 5000's are not liked by a lot of people but I only have experience around the 5000N's and I see them getting carted off to the shop on a regular basis. So I guess you will be in about the same boat no matter what color you pick. Not all TN's have problems and if they do NH does take care of you. Also, not all JD 5000's have problems but I do not know how JD is for warranty work. I know their parts are not too bad for my JD M. As for parts prices, AGCO is the worst around here which is sad.
In the end, I will be buying another tractor to compliment the TN and it will be a NH. Most likely a TS or TL because of how well my dealer takes care of me. Take care.