A friend of mine is considering whether to buy a truck camper or other type of RV. He asked me a bunch of questions, including some which were identical to those I considered in my purchase decision. Thought it might be useful to others to share my response in this post. My response is obviously based on my experience and needs; since everyone is different, the best advice I can give is to conduct thorough research, talk to a lot people who have RVs, and rent before you buy.
I started out sure I wanted a truck camper because, like you, I mostly like to camp in State Parks (SPs) and National Forests; whenever I see a truck camper now, I'm so glad I changed my mind. While the benefits are obvious, I've decided truck campers are too small for long-term camping like I'm doing. I can't imagine 2 or more people camping in a truck camper, especially when the weather is bad and one (or two:) is stuck in the camper! Also, I really like the ability to park my AS, unhook in about 15 minutes, and go somewhere in my truck; much more complicated in a truck camper. In addition to stability concerns, the primary safety reason I didn't get a truck camper is because they (at least the ones I researched) are heavier than the manual in my 3/4 ton GMC 2500HD says I can carry. I went round and round on this issue with a truck camper dealer and I'm well aware that a lot of 3/4 ton (and even smaller) trucks are carrying truck campers. The deciding factor for me was - what if I was in an accident and the insurance company wouldn't cover me because I exceeded the manuals weight limits or there was a lawsuit which revealed that my camper exceeded the truck manufacturer's weight limits; this scenario scared the heck out of me.
The AS has been great! Initially, I looked at a 19-footer, then put a deposit down on a 23-footer. At the last minute, I changed my mind and upgraded to a 25-footer and am so glad I did. Having the extra room is critical for long-term camping, especially when the weather is bad (turns out this happens a lot more than I thought). Besides space, another big advantage of a larger AS (and compared to truck campers) is the larger holding tanks; about 39 gallons each for black, gray, and fresh water. These large tanks allow me to boondock for a week without hookups or dumping! Also, the larger AS has a larger flat roof which allowed me to install 3 solar panels (350 watts) which charge my 4 6-volt batteries.
Other things I like about my AS - they have been around for 75 years; I've talked to several people who have trouble finding parts for their RV because the company went out of business or are no longer making their model. The dealer and AS have been great. Using my AS full-time I've found a few minor things and they have all been fixed for free under warranty without complaint. Little things like a leaking pipe under my sink, the solar wiring system needed to be upgraded, a couple of door knobs needed to be reattached. As I understand it, it is normal for a few things to need repair during the first year of service of an RV; having a reputable company and dealer was a comfort to me.
It also seems to me like the company has used their 75 years of experience to improve the design and functionality of systems and space within the AS. Having lived in my AS for 4 months, it makes sense where and why things in my AS are designed the way they are. ASs are also easily recognizable; I can't tell you how many people come up to me and say - "I love ASs"..."they are the premier RV"; great conversation starter. Also, since I didn't/don't know how long I'm going to be doing this, I wanted an RV that I could either easily sell without a huge loss, or easily live in long-term; the AS seems to cover both options better than other RVs. Judging from others, it seems there are quite a few RVs out there with quality issues so my best advice is to thoroughly research your options before purchasing. If you look around, you'll also find a lot of used RVs; the used ASs seem to be few and far between.