My fan is loud when I'm in my home office. On the road at any other place I can't hear it!
You know why that is.
The hinge story is simple. So far the only cranked hinges are ones that are old or abused. These laptops are fine short lived things so once you figure out you get 3 to 5 years you are better prepared for the eventual death.
But that Apple http://www.google.com/#&q=MC700LL&fp=1 is something of a tank. While I think it may get many more years I doubt you'll get 10.