Thanks for your reply Doncha. I suspected as such…

I hope I can ask one last question, but one of our sites receives about 20,000 comments monthly.

Am I right in assuming if a user has left a comment, they have a WP cookie set and therefore don’t receive a cached page?

On that site, commenters make up a high-ish proportion of users.

For this reason we’re using w3 for the db and object caching it offers, but I’d love your view on how Super cache performs on a high comment site.