I have the MK II 35mm... I use it almost weekly... I also have a pulsar 19hd for scanning... The Image with the IRD is amazing. Yes, I wish it had auto NUC, but I've heard the reasoning is that you don't want it auto NUCing as you are about to take a shot. In the beginning it bothered me somewhat, but honestly, it hasn't been a problem. When I first go out, I might have to NUC it several times, but once it reaches a good temp equilibrium, I really don't have to mess with it much. I ran lithium batteries and would get a full nights hunt out of them. Lately, I have been using the UNV USB power pack adapter and can go a full weekend. It's a bit of a PITA, with all the extra cables and such, so I am thinking about just going back to battery.
My main complaint, and it is with all thermals... I would like it to be able to record video internally. It's a hassle to deal with attaching a mini DVR. I've had 2 go out on me and have pretty much given up on recording my shots. I am sure that will be in the future though
I like it so much, I am saving my pennies for a second one. VERY good bang for the buck!