The one thing you need to be cautious about is the danger that a page that has a place for a user to enter information in. Say you have a page where a user chooses a,b, or c. The user that first hits the page chooses b. As long as the page cache exists, any user that hits the page will see b already checked. Or let give you a real world example. One of the sites I managed used another kind of caching (but principle still applies). We began to get reports that people who went to the site, read the page, and wanted to leave comments would see that the comment form was already filled out with another commenter’s credentials and comments. This has been years ago so I don’t remember what our fix was, but the result was the same. So regardless of the caching solution, its something you need to watch out for, especially dealing with credit cards, etc. Like my dad told me years ago when I got my first job “You’re screwing with someone else’s money. Be careful” (actually thats a sanitized version. His language was far more colorful lol).
So, I guess I’m saying be cautious and watch for problems, regardless of which caching you use.
tim