I have an Airstream and am very happy with it. This thread is starting to take on the brand hating you often see in the tow vehicle forum.
The Airstream is a very well made trailer but so are many others. It is different in so many ways and not all of these provide advantages. I have a 25 footer and it has plenty of storage inside the trailer but very little, almost none actually, on the exterior. It is comfortable for us but not lavish as many other box trailers are. I personally am not interested in having a fire place, a kitchen island or a huge television in my trailer.
All trailers need care and yes, an Airstream will leak if not maintained. I will submit that while this happens, it doesn't happen as much as the regular box trailer out there. I am a member of the Airstream forum and yes, there is much talk about water damaged trailers but when you look, these are trailers still in use after 40 or 50 years. How many 70's vintage AFs are still running around?
Airstreams are no better than most others when it comes to most of what is inside. The plumbing is home quality but the appliances are the same as other brands. But, when it comes to towing, the Airstream can't be beat. I used to pull a 21ft hybrid and now I have a 25 foot Airstream. I get the same mileage and it tows much better. The design of this thing is amazing and if you are actually someone who pulls your trailer a great deal, the Airstream will be an advantage.
I went in to buy a personal computer once and saw three similarly competent units. Unit A was a cheap PC, unit B was a much better PC and unit C was an Apple that was much more expensive than either of the other two. I asked the salesman why such a huge difference and he said, "If you buy A we will see you back in about a year with some kind of trouble. If you buy B we will see you back within two years. If you buy C, we won't see you again." There is a certain amount of value built into the top of the line trailers out there. While it is not always true, you usually do get what you pay for.
By the way, I am also an AF fan. They make a great unit. Oh, and as far as cost goes, I purchased my 2006 in 2009 and saved about 40% off of new price. Today, I can sell it for what I paid. I think in another 10 I should also be able to get a very fair price.