I used this to slim down my largest WordPress site prior to moving it to another host.
The site had grown to a not insignificant size of 100Mb - and this was causing me great concern due to phpMyAdmin's Import limit.
I set the plugin to keep just 1 revision of each post/page; delete all trashed and spammed items;and to optimise ALL tables.
After running the optimisation my database shrank to 13Mb!
Definitely recommended.
