Cache warmer is useless i explain why :
without cache warmer :
The first page that load by an visitor generate a page cache that is serve to all the next user
with cache warmer :
the first user have already a page cache served
–
But the question is : if you set your plugin to don’t delete the cache periodically
cache warmer is simply used for serve that One and Only user the cache.. croon job and server load for nothing !
cache warmer is usefull if you have a site with 10 000 visitors at the same time who want to view différents pages where the cache is not generated yet then 10 000 visitors load more the server than the croon job of the cache warmer
the best is to set the plugin to not delete the cache and anyway when a page/post or else is updated or new the hompage cache and the rss and the page/post in question is cleared so cache warmer suck ^^
The best config for simple configuration is
Gator cache (prégénérated cache)
Db cache reloaded fix (DB cache)
Html minify (https://github.com/cferdinandi/html-minify)
and if you want to push the thin a litle more better wordpress minify for js and css)
the add a good caching sequense in your htaccess.
voila !