What I was trying to say is that score in the individual review is not very useful, but if there will be 20+ simple reviews of the same knife with scores, then they start to make a better sense. But to be able to accumulate a big number of opinions, the review process needs to be as simple as possible. This is just my opinion and nothing more.
Here is a simple form that I put together is 5 minutes that I think might work:
http://www.2shared.com/file/9305301/7a7b76a7/knife_review.html
(click save to PC at the bottom. Sorry, don't know a better place to upload stuff)
You could also add a place on the same form for a full review (probably will be without pictures) for those who are less lazy and want to share their thoughts. Then add "WAS THE REVIEW HELPFUL" button to each submission, so that the best and most useful review will float up to the top of the page.