The best review is the disinterested gameplay video review that aims at just showing the game and not selling the game or making a movie out of it.
It's just a short step away from a demo, and if you want to take it one step beyond then there exist these days a very thorough type of gameplay video called "Let's Play". Watching a good, commented, "Let's Play" series is nearly as good as playing the game itself.
You can find many good ones here:
http://www.letsplayarchive.com/
Unfortunately there doesn't seem to be any Let's Play at all (good or bad) for Silent Hunter 5 anywhere on the internet, though there are some gameplay videos here and there.
Volunteers?