Another time saving tool from NoNumber. You can set so much rules to place or remove modules that you can play hours with it.
Exclude, mirror, browser based...so much fun.
The coloring stuff is really useful when you get tons of modules. Used it in a 50+ modules site, couldn't have survived without it.
And the J!3 version is just great.
I have experienced slight slowing issue and validate.js unresponsiveness, due to bad extensions symbiosis, lots of menus and mootools but was not really faster without it.
Makes you feel free.