Just upgraded from an old version, and I like the new look/features, but after I disable the cache ("Cache hits to this website for quick access"), I can no longer get to the "Delete Cache" button in the [Tester and Contents] tab.
Since I use mod_rewrite to serve cached files, after I disable, the cache files remain in place and being served. I can certainly delete the cache then rush over to the Advanced tab to disable caching, but it's a race between me and visitors. If certain page are active, they'll get cached before I can disable caching. If this happens, tools like validator.w3.org will get the cached version, rather than my changes after disabling.
One solution might be a checkbox to "always delete cache when disabling caching".