Interesting. I haven’t noticed any performance impact. I’m using it on fairly beefy general-purpose machines though.
Maybe you could work around this by using separate search and address bars? Then you can search before tab and container creation happens. Not gonna help for standard direct navigation though.
It most often bites me when I'm in a new tab and I'm trying to complete a site URL from history. AFAIK there is no other clean way to open a new tab of a site you've been to before. Maybe if the history sidebar were useful, but using that is a PITA for me because I'm already using the Tree Style Tabs sidebar (which is really a feature that should be implemented in firefox itself..)
Maybe you could work around this by using separate search and address bars? Then you can search before tab and container creation happens. Not gonna help for standard direct navigation though.