Wordpress - Caching Plugins Revisited

We've been using "quickcache" for ages, after a nasty experience with wp-supercache. (it ate a website!) Anyway, we've been doing some back-to-back testing on two similar websites running different caching plugins. The results were: Fastest: Hypercache, with browser caching and compression turned on. DB Cache didn't seem to make any difference when combined with hypercache. Had some issues getting rid of quickcache, as well. Had to switch off cacheing, then disable, then delete, then edit wp-config to restore the cache setting.. Google Page Speed scores have risen from around 70 to around 89..