TSO,
while mine is an open station, I can speak to the soundness of the TN series. I bought my TN70A new in 2008. It is a 2007 model, and I understand that was the last year they were built. NH replaced them with the T4000 series. The T4030 would give you exactly the same tractor, with 6 more HP, a different model number on the side of the hood and about $8000 more on the price tag!!!
Mine has close to 1000 hrs on it. The only repairs have been: replacing the rockshaft seal and bushing on the right side of the 3PH, (from using a hay mower); replacing the rubber valve stem on all 4 wheels; replaced the fuel cap (the original split); and the hour meter quit a couple years ago. (it would require replacing the entire instrument cluster to fix) That's it. It's never been back to the dealer. The tractor really operates very smoothly. It has a tight turning radius and a synchronized transmission. The IVECO 3-cylinder engine is great, and really fuel efficient. Even though I have 3 cab tractors (JD), I still use the TN70A to stack hay in the barn. It's a bit smaller and easier to maneuver inside the barn.
In 2010, when I was shopping for my first cab tractor, I was really happy with the NH, but didn't buy blue again because of the comfort of the JD cab. I'm a big guy: over 6' tall and 250#. The NH cab felt small compared to the JD. But that's just a personal preference.