one of the things about the A Liner is opening and closing and having to stow stuff when it is closed. I have used one a couple of times, as the base I work on has them for rent. They are super easy to pull, a little challenging to back (so short), but do require setting up before use. I really like that I can load my TT over several days without doing anything more than opening the door. In my opinion the A Liner is too much like a popup, just has harder sides.
It really depends on what your plans are. I just talked to a co-worker yesterday, who had rented the A Liners several times, and said he and his wife had decided on a regular TT.. because they didn't have to set up and take down. He has a SUV to tow with and just chose a 15 ft TT that was well within his weight limitations.