For me, a) pentadactyl is better than Vimium, b) FF seems faster (I know, subjective), and c) Mozilla is much less likely to have been centrally logging something about me without my explicit permission.
I use it for the history search in the address bar, it seems to remember far more history than Chrome which is really useful when I'm looking for that StackOverflow thread I read the other day.
My was one issue with Chrome: it didn't have the magic history search in the URL bar that Firefox.
UNTIL I discovered that if you disable "Use a prediction service to help complete searches and URLs" option for the Omnibar it works PERFECTLY, just like Firefox. Type in any part of the URL or title of the page and bingo.
As noted in the description, this extension resolves that permanently, although I'm still not quite sure how it impacts history sync or URL bar search.
I also think (totally unsure) that you might need to open the extension occasionally for it to save the history.