We have a 2007 John Deere 8230T with 3200 hours on it. Total breakdown cost in its life span is up to $9000, because the turbo went out of it week before last ($6000). All in all I don't really like this machine, it's too big, heavy, and a pig on fuel. Reasoning for buying this machine is that it was the best option for us at the time. I would not recommend a T track JD unless you can get a good deal on one and have a trail system that has no swamps or light duty bridges.
What else is out there...
I personally have had really poor luck with Tuckers. They have there place, swamps, and deeeeeep snow. Lots of track problems which are pricey. I have not been around the other brands tracked snow specific groomers enough to comment, but have heard of lots of problems with all. You know, if it has t!ts, tires, or tracks it's gonna cause you problems..
My $.02... Tractors with Soucy tracks seem to be the answer. They are not bomb proof, but seem to be the least costly for maintenance (but still up there). I like John Deere ag equip. Have had better luck with them, and they are the most comfortable, user friendly tractors out there.
The other issue one has to look at is dealers. We bought our tractor from Voelker Implement in Lake City MI. That's 5 hours away on a good day. There is no JD ag dealer in the UP. We use Bader and Sons for any of our needs out of Lower MI(6-7 hours depending on store), because they have better service. Have a good dealer because it really matters.
Think snow! -Dave