I've read comments by many folks over the years who seem to be happy with their A-liners. That said, and having had a veritable parade of campers and mohos including two pop-ups (and my folks having had several when I was a kid,) two class B-vans, two class C mohos, a Class A, nine or ten fiberglass "egg" style campers, and seven Airstreams over the years (long story... but I got a LOT of experience with them,) my take on pop-ups in general is that they have all of the disadvantages of a tent and none of the advantages of a travel trailer.
I lived full time in a 1970 Airstream Safari Special 23' single axle trailer for nearly a year back in 1987 in San Diego County where the weather is generally balmy. During the winter, I'd burn through two 7 gallon tanks of propane in a week running the furnace. 23' (20' of living space) is the smallest trailer I'd want to try that in. I had an '06 25' Bigfoot trailer for nine years that was just about perfect size for full-time living, yet easy to tow. 25' is the sweet spot for many folks... my current Born Free moho has about 25' of living area with a 32' LOA. The biggest challenge in four seasons living in an RV that's meant for short 3 seasons occasional use is a)staying warm, and b) running water. Very few RVs have four-seasons capabiiity, and fewer places that freeze in the winter have four-seasons utility hook ups. You can't wash out your sewer hose without running water at the dump station, for example. And how do you keep your dump valves from freezing (and cracking) if they're exposed? It can be done, but not easily.
After nearly sixty years of camping and traveling under my belt (my first recollection of camping was sleeping in my folks' new '59 Rambler with fold-down seats) I now have the two mohos listed in my signature and I'm really pleased with them. Different types of campers work better for different kinds of camping, family size, and travel, and those needs change as families, destinations, and reasons for travel change.
Happy hunting!