They are much more secure then tentage, especially in foul weather. Just don't erect them in high winds without one of the "wind kits" that are readily available as a sudden high gust of wind can severely damage it. After erected they can take some very high winds - I think as much or more than a regular box shaped TT.
The foam seals need to be replaced every few years as they do weather and age over time. This is a simple and inexpensive procedure you can do yourself from foam weatherstripping from a big box hardware store. I've had mine since 2006. All campers develop small leaks over time that will need to be calked. The Aliner probably less than most. If all the seals are intact water cannot get inside, however I recommend cracking a window in cold weather, regardless of what kind of heater you have as the moisture in the iar will condense on cold inide surfaces causing dripping inside.
Overall, we are very happy with ours. Ours is the XLE model which is the loaded one. There is very little room to move around inside but you never feel claustrophobic because the cieling is so high. I'm 5' 11" and I can't even reach the peak of the cieling on tippy toe - and I have the low wall model. The high wall model has even more room inside, as do models with a dormer.
Here's a few shots:
Here's one of the kitchen, galley area. Note microwave, 3 burner stove and 3-way freezer/fridge that runs off of propane, 12v d/c and 110 a/c power. To the right is the shower/cassette toilet area. The cassette is easily removable from outside and holds about 1 week's of bodily waste. It can be easily and cleanly dumped at any dump station or toilet - you don't even need gloves like a typical RV.
Here's DW sitting on the sofa that transforms into a king sized bed. We added a 1" memory foam topper to the bed to make it super comfy.
Here we are set-up at camp. BTW it takes 30 seconds to pop-up on the side of the road for quick lunch and potty breaks. Setting up a complete camp takes longer, of course. Popping up and over-nighting in roadside rest areas is a piece of cake, something you would probably not want to do in a cloth sided pop-up that takes maybe 20-30 minutes to get fully set-up.
I pulled it with a 2.4l Chevy Cobalt till this year when I switched to a F-250 in preperation to getting a bigger trailer. The Cobalt's gas mileage drops from 31-34mpg to 22-25 when towing. My F-250 diesel gets 17-19 towing. The motorbikes in the bed get 100mpg and will hit 60 mph. Here I am at 2 different tips to Big Bend, NP, overnighting at the same roadside rest area on both trips with different tow vehicles.
They make bigger and smaller models. From this:
to this:
The latter are from the Chalet XL series with dormer.
Chip