We'll see how this holds up. I currently have nearly 3283 tabs in my primary Firefox window. (The other six windows only have 35-125 tabs at the moment. I sort of use the windows as tab groups.)

To its credit, Firefox is the only browser that does not either slow to a crawl or just fall over dead with that many tabs.

I still need a good tool to merge bookmarks from a bunch of older Firefox profiles, though. Does anyone know of a good tool to do that?