Dave Hyatt, now one of the core developer's on Apple's Safari web browser, has posted an excellent read about tabbed browsing - covering various user interface issues and different virtues and problems that exist with all current implementations.
When I use Safari (which lately has only been at home - Safari v60 has some weird network bugs that make it difficult to use with many dynamic sites and servers, it seems. I've stuck with the previous beta (v52) on my iBook and iMac), I don't miss tabbed browsing. But, due to the Safari v60 issues I just mentioned, I've gone back to using Chimera (and am looking forward to using Camino 0.7 tomorrow) at work, and have fallen into the land of tabs again. Usually, I have our issue tracker open in one tab, the Zope management screens for whatever project I'm working on at the moment in another. Rarely do I use other tabs now, although sometimes I keep a Zope Error Log reporter tab close at hand (in Safari, I usually keep a minimized dock window for this purpose).
One thing that I have noticed since going back to tabs is that there are problems with the UI. I'm used to using command-tilde to cycle through open windows in Mac applications. Sometimes, I cycle through my Chimera windows rapidly looking for my Zope Management screens and wonder why I'm not seeing it. Only after a couple of cycles do I realize that it's in one of the windows, but in another tab then the one being shown. So it's command-tilde to switch windows once or twice, and then the command-shift-[ (or command-{ ) to switch tabs when I land in the right window. It's a mild annoyance, but it's happening to me a lot lately.
Which is why I think Dave's post about various tabbed browsing implementations is such an interesting read. Tabs are handy, but their UI can be awkward. So, I remain on the fence now. If tabs show up in Safari (and the issues that I've reported to Apple, especially about v60) get addressed, I'll use them. If the few bugs with Safari get fixed and it stays lean, easy, and fast even without tabs, I'll use it without.