Eric:
After many conversations with Kubota, American Engineering, in Torrance California, I think they are following my advise about shrouding the area between the radiator, a.c. evaporator and the oil cooler. There has been a Kubota rep out to look at my 5030 too.
I guess they want mine this summer as they are going to do some tests on it (maybe they can have it, I haven't decided yet).
With the fix, the a.c. is impeccable.
On the subject of loader controls, the 5030 has the 4 way valve with a joystick (mechanical/cable linkage). It's very easy to modulate and the stick is in such a convenient place, it falls right into your hand. It's really a joy to use. I suggested to Kubota that a swivel seat would also be in order. I spend quite a bit of time backing and while the mirrors afford a good view, a swivel seat would be even better.
Overall, I am quite pleased with the unit. I'd opted for an M series, cab unit, probably in the 70 horsepower range, but the 5030 HSTC is actually LOWER in overall height than the non-cab, ROPS equipped 5030. Height was a prime consideration as I keep the tractor in my heated shop and 8' was the limit.