It's actually surprisingly stable and usable. Which may contribute to the problem ;-)
Tabs only load once directly viewed, so a session restore opens pretty quickly and doesn't actually use all that much memory. After a time, as more tabs are visited (and yes, I really do try to shut some down with time), the session eventually gets less usable, though that can take many days (I've not tracked this).
Moving and searching within the tabset itself is another part of the challenge, though at least Firefox will prompt if you're opening URL that's already open elsewhere. (Chrome ... fails at this.)
I found that Chrome destabilized and black-screened a lot when I had 1500+ tabs open, but Opera oddly enough did not. Opera seems to have slightly better memory management and background tab handling. (Puts them to sleep better.) That said, it does still take a very long time to reopen that many tabs. That's where stability comes in... you don't want to have to close and reopen your web browser throughout the day, if you can avoid it.
Opera does indeed have switch to tab, FYI - and open tab searching.
Tabs only load once directly viewed, so a session restore opens pretty quickly and doesn't actually use all that much memory. After a time, as more tabs are visited (and yes, I really do try to shut some down with time), the session eventually gets less usable, though that can take many days (I've not tracked this).
Moving and searching within the tabset itself is another part of the challenge, though at least Firefox will prompt if you're opening URL that's already open elsewhere. (Chrome ... fails at this.)
And yes, of course I'm using Tree-Style Tabs.