It seems to me that tabs + bookmarks doesn't quite cut it. Perhaps with the exception of pinned apps we need to move away from the idea of 'open' pages entirely and really rethink how navigating the browser's history works.
When I hit the backspace key, there is a significant probability that I will have to wait for the old page to download and render again. (Wether the re-download and re-render happens seems to depend on how the maintainer of the web page set the cache-control.) Although I understand the advantage to non-technical users of doing things this way, as a technically-adept user, I would have preferred for the back button never to cause a re-download or a re-render. (I know that I would have no trouble figuring out when manually to cause a re-download (using e.g. the reload button) because that is the way Lynx did it years ago.)
My point is that the main reason I open new tabs is so that I can definitely return to the current page without waiting for the page to re-download and re-render. I would be happy with the back and forward buttons and the history menu if using these things did not often cause me to wait.
* Especially when searching Google or reading HN; I'm more inclined to navigate back and forward between results rather than middle click everything into new tabs
The proposal is remove to tabs completely, replace with a richer, searchable and better cached history, improved bookmarks, which are better organised for returning to recent items, and a page queue for yet to read items. I would like to try something like this, it seems really interesting.
Generally, tabs can be seen as a flexible mechanism that is used for a range of tasks none of which they are optimised to cater for.
Although, I'm not sure about their proposed solutions. The history is really lacking in context and could maybe be displayed better as a tree of thumbnails showing you not the order pages were opened but from where they were opened. I think the queue is a great idea but could probably be built into the same tree; just highlight queued and bookmarked pages in some way.
Because I use my browser this way, I finally had to move from Firefox to Chromium. Chromium manages memory and CPU WRT tabs much better than Firefox.
I don't really like Chromium, but I got tired of listening to my laptop scream.
(This may be a recent thing. I'm running FF7 and it's definitely better on memory handling.)