That report sounds interesting, got a link by any chance?
I would think that session resumption should greatly increase performance for clients returning to your site, because there's no need to do a complete handshake (which is - relatively speaking - resource-intensive and IIRC also requires more network round-trips).
Wouldn't it be easier to just disable TLS resume than to figure out how to do it right?
edit: It was another agl article, https://www.imperialviolet.org/2010/06/25/overclocking-ssl.h...: