Why should one use bookmarks rather than many tabs? I have many concurrent projects going, and things I refer to regularly, so I just leave them grouped in my tree of tabs on the sidebar. Much more efficient than digging through nested bookmark menus, or trying to make sure the bookmarks are properly classified.
Basically, my tabs are bookmarks, except tabs are integrated into the web-browser better.
If they would make the tree-style tabs very aggressively swap to disk, or even discard state entirely and seamlessly become a bookmark that would reload when clicked (perhaps this behavior could work only for white-listed domains, like wikipedia.org), that would be perfect.
The main usability problem with bookmarks over tabs AFAIC is that the bookmark UI does not encourage pruning bookmarks, so most become stale over time.
Another idea I've been kicking around for a while is "tab decay". Have tabs start to decay and close themselves after not being viewed for a configurable amount of time. 1 month would probably do it for me, it would save me a lot of cleanup time.
Yes, that is true but there is no problem with just 60 tabs. I have 260 open tabs and my browser is not sluggish and the memory usage isn't too bad either, 3GB.
Basically, my tabs are bookmarks, except tabs are integrated into the web-browser better.