Splendid idea, and good execution, so kudos!
I think it is very good not only to count the reviews, but also apply some qualitative criterium. I wonder though how that works.
The like button comes in mind, but also the funny posts are being liked (at least by me) so it can be safe to say that not only the quality posts are being filtered by the 'like' button.
Oh, and a color scheme thingy. In the YC Dark scheme the names are hard to read.