Air con is standard on XR model utes not on others. Why I don't know should be standard on everything these days.
Not 100% sure on the technical difference between Prestige and Premium audio but I know Premium has the colour LCD screen in the front and Prestige doesn't. I guess Premium has better speakers, higher output and so on. This might not be possible in the ute due to having no rear space for additional speakers, sub, amp and whatever else Premium has.
Not allowed a sig?..