Looking at the evolution of epinions, it seems to be shifting dramatically away from user reviews toward being a showcase for distributors and manufacturers, but if you dig for them, there are still lots of good tips. I don't think you could make a living writing reviews for them.
It covers a wide range of products, but is somewhat superficial. If you need to make a quick decision on something you haven't had the time to research properly, it's a very good site. I like being able to read feedback from actual users as opposed to mere marketing fluff.
CPF is more specialized and 'deep', with lots of experts, modders, users, designers and manufacturers. It's quite interesting to watch the interplay between designers and users -- it's the way it should be if you're a flashaholic. People contribute because of their interest, not to earn money on review-writing.
It does take, although, a while to let all the info sink in and make decisions about what you want to buy or do.
