Too late to edit my post, but "where Google has clearly invested time and money into optimizing things for FF" should read "where Google has clearly invested time and money into optimizing things for Chrome."
Personally I feel it is worse than that: there have been som issues so bad that I hardly get Hanlons razor to work at all, notably one where just having a search result page open in Firefox would consistently spin up my CPU for no good reason twice a minute.
(Of course there were a number of other weird lagging issues as well.)
Sorry.