I haven't tried Firefox Sync since I discovered early-version failings, but I should try it again.
I use Firefox as my default browser, but when I discover favorite websites, I load those into IE as my master bookmark-favorites keeper - since all browsers claim to import from it, and it offers few import abilities on its own. And has Harley and others have mentioned, many money-sites have simplified their programmers' toolboxes by only subscribing to IE encryptions, so I imagine I'll always have IE loaded somewhere. Just with few uses (money sites, visiting Microsoft, letting Ballmer and BillG know what I think of them, etc.).
So IMPORT remains important and it irritates me that they've got an IMPORT module for some versions that worked perfectly, and then other versions use bad code, bad quality control, bad oversight and bad corrective measures.
But Firefox still offers me a lot better features than its competitors.