For large setups involving multiple pieces of software used in conjunction with WordPress, would you recommend integrating the functionality of each one of them into a single system, so that the same theming system could be used across the board? Or is the hit in performance too much?
And if there is a hit in performance, what systems are available which are able to cache the pages to avoid this problem (ie:
WP has supercache, but I don't know if other systems like forums have such facilities available for them).