I just took a break making hay and was "lurking" myself.
It's me with the AC problem, but it's fixed (myself). I guess it don't get warm enough up there for the AC to work hard and as far as your dealer, have him call Kubota in Torrance, California, they know about the problem. I'd say your dealer is blowing some hot air himself.
I just finished bailing in the field and it's 80+ here. No problems.
The other fellow that wants a price quote, well, I'd opt out of the radio. The cab unit comes pre-wired (the leads are in the left upright (facing forward). The Kubota radio is inflated to say the least. I had my dealer install a Panasonic am-fm weather band (which I need in the field) for 1/2 the list price of the Kubota radio.
The rear wiper also comes with a defroster grid. get the front and rear work lights they are really bright.
I am against loaded tires, heck, I drag around hay mowers, balers and rakes and never had needed them. I'd not get a 5030 for tillage work, it doesn't have the power for plowing or the weight. It's been said numerous times on this site, BUY FROM THE DEALER WHO WILL GIVE YOU SERVICE AFTER THE SALE. I'm not saying you will ever need the dealer, but I don't buy on price alone. If you are so concerned about getting the lowest price, maybe you should step down a model that you can realistically afford.
Andy, I like the TN's, you know I run NH haying implements, but, the TN series is a bit more money and the TC's have no comforts like a cab. I am always jabbing the local dealer about that. We just picked up a new BR 760 rounder today. NH is at 0 percent on Ag equipment for 3 years.