I backup book marks in a few ways. I never trust online services to do it for me unless I have to. If there’s an export to CSV / JSON or some nice Chrome plugin that exports, it’s worth it.
Opera’s super fast, although I think that’s only when it’s loaded. I seem to remember versions over the past few years have a longer load time than it used to. But once it’s loaded it’s fast and doesn’t hog up your memory. Plus it plays Youtube videos better than the rest if I remember. [I haven’t used it in a few months but I should ]