My husband and I have had two A Frames. We first had an Aliner Classic (12 foot box), but we found it to be too small. We sold it and bought our current Aliner Ranger 15 (15 foot box). We like it a lot. It tows great and sets up in a minute. If our budget would allow, we would have gotten an Aliner Expedition with two dormers.
You need to decide whether or not you can exist in a small space. We're outside a lot, so it's not a problem for us. We have a 60x80 queen bed, a large dinette (makes into a very roomy single bed, when needed), a Cool Cat heat pump/ac unit (central a/c and heat with digital thermostat), sink, hot water, fridge, stove, microwave, cassette potty, outside shower, and several cabinets for storage. We also bring along slide out Sterlite drawers for clothes and dry goods, an easy up, a camp kitchen for cooking outside (complete with electric frying pan and small electric oven, and an electric ice maker. We bring a t.v. if we'll be in a place with a cable connection (Aliners don't have t.v. antennas, but they have cable connection). Yeah, we like our creature comforts!