Any way to tell what addon uses the most CPU?

[Octopuss]

I don't suppose this is technically possible, but just in case...

[sirinsidiator]

Not really.
You could try to write down your average CPU usage in certain situations, disable all your addons, write it down again and compare. If there is a huge difference you try it again with half the addons disabled and then the other half until you find which addons are causing it.