Sloooow Not yet rated
Happily used this extension for some months - but have now had to remove it as it was causing FF to run very slowly & generate script timeout warnings.
Recently upgraded AV software to ESET NOD32 v3 and found that FF was running very slowly. Reinstalled FF and extensions & it ran at normal speed at first. Then I had to upgrade a couple of extensions - not, so far as I remember, Extended Cookie Manager - and found FF running slowly again. Disabling Extended Cookie Manager resolves this problem, so I've now had to uninstall it.