Is de-lamination a big problem? Can Azdel help?

I am researching to buy my first travel trailer. I have looked at the pros and cons of aluminum vs fiberglass and have decided I would prefer to go with a fiberglass exterior. Now I have questions and concerns about the de-lamination issue.

First, is it a problem that happens a lot? I understand that the underlying cause would be water leaks, so if you prevent leaks, then no problem. However I am aware that water will usually find a way.

Second, Coachmen is producing TTs with a product called Azdel. Instead of using wood in the sides to attach the fiberglass laminate, they use Azdel. As explained to me by the salesman, with a wood backing, if water gets in, the wood absorbs the water, expands, and presto you get de-lamination. Azdel does not absorb water, thus it will not expand and de-lamination is less likely to occur.

It sounds reasonable to me, however I am not an expert. The salesman could be just "selling" his TT and feeding me some, well you know what. (On another issue, I am amazed by the number of sales people I have run into that do not seem to know their "stuff". This guy seemed pretty knowledgeable.)

So any experience out there with the de-lamination issue and the pros-cons of Azdel? Thanks!