Thanks everyone for the replies and first hand experience. Its kind of what I expected - that the few stories I have read were very much the exception. In fact, now that I'm thinking about it, I think the one story I remember in particular the trailer had been used quite a bit over the course of 8 years. It was the drain line elbow, not the hose itself.
To answer the question... the ones I've seen pictures of are on a "race". There's a bundle of supply and drain lines as well as electrical cable if I'm not mistaken. There's a half-loop of slack that is secured to a slotted piece of metal that keeps it all in line when the slide goes in or out. Looks pretty low-risk to me but I can see where it does get a little more "exercise" than it would in a stationary location.
Based on the feedback here and the relative low number of bad stories I've read, I think I will add kitchen-in-slide models back into my list of considerations.
Thanks again everyone.
Dean
