I have had an Aliner for the past 10 years. For me it is a "travel trailer" for two not a "family camping trailer". By that I mean it is great to tow behind my SUV, I almost never stay more than three days in one spot, and many times its just overnight and never unhooked. The quick setup makes it ideal for traveling but I will agree that the interior space is minimal, especially for more than two people. The hard sides provide some added security as well as no wet fabric to fold. So for me the Aliner is a specialty market, but I have seen a family of four camping at a state park in the smallest one, the Alite, and having a great time - Different strokes for different folks.
I do also have a semi-folding Starcraft hybrid for times when I plan to stay many days at one place rather than just travel. Much more spacious interior with a real bathroom and shower.
My Campers.