[robski]

Down a different avenue on the photozone site mentioned above is

http://www.photozone.de/active/survey/querylens.jsp

This is based on user input instead of a professional review. However, it covers a very wide range of lens. Various lens factors are given a rating out of 100. If you use it as a rough guide it will give you some idea if the lens is a lemon, OK or Top draw.