Welcome to the forum
@michael d
We had a 16.49.3 with a club lounge and found it nice and comfy but it did make it a bit squeezy to get into a seat and getting into the front bed.
Currently have a 17.56.2 with a dinette style setup and although not as comfortable it does give more room (Also has the smaller dinette for the grandkids when any of them come away with us)
The 2.2 Heron aircon in the last van was OK but did need to make sure all vents, windows etc were closed. Have roof mounted Truma aircon in the current van and find it a lot better. If you do get one with the wall mounted heron and it stops for no reason..... UNPLUG it and take off the front cover. There is a small white plug behind the cover that apparently has a tendency to vibrate loose (Only happened to us once in three years though)
12V for running the fridge is only for when traveling and make sure it is wired to the car and not the van's battery. They will kill the battery's charge in a matter of hours. Run it on 240V or gas only when parked.
The first thing to look at is under the mattress's when opened up and look for any water stains on the bottom of the mattress and/or the timber base. If there is a lot walk away as that means it has (or did have) a major water leak at some stage.
Apart from that make sure you run and test all appliances etc. Ensure you look at the van with water hooked up and turned on etc.
Plenty of info on here so have a good look around and if you can't find an answer just ask away!