Is the Clickbank review sites are still in play? I have some domains and I can build a good review site and maintain as long as it generates me money.
Ofcourse they are still effective. Just pick up a good product and write some honest reviews in your niche.
They are common these days, So, if you are building only a review site then you have to be quite unique which is a hard thing to do in this case. So, people avoid them generally.
My suggestion is that build a normal blog or site and give review of the products in them. Just don't build an entire site for just review.