As someone who switched to Chrome from Firefox a couple years ago (IIRC), I couldn't be happier to have made the change. My main reason was that Firefox kept losing all my open tabs despite being set to save them on exit, and that there was no way to get them back (e.g. from the history). I had a bunch more reasons, but that was the one which finally got me to try Chrome, and in the end to switch to it permanently. (If I accidentally closed the window with my stuff in it while still having another one open, I could hit the 'reopen closed tab/window' command to get it back. If the computer lost power or something really unexpected happened, it offered to restore the session (as Firefox ordinarily did, but frequently failed to do). Once or twice I managed to accidentally lose my tabs myself (shutting down all chrome windows without noticing that I had more than one, and they shut down in the wrong order), but since sites are re-added to the top of the history when they are opened in the browser on startup, I was able to just re-open them all from the history (something I could not do with Firefox since it didn't re-add or move their entries to the top when the browser was reopened and the last pages opened, at the time I switched to Chrome, anyways).
Firefox had other issues, but I'm not sure how many of them have been resolved. For instance, its version of javascript was much slower than Chrome's, if a tab froze all of Firefox froze, if flash crashed, it stopped working in all tabs until the browser was restarted (it crashed in chrome for the first time in recent memory while I was listening to music a few days ago; I refreshed the tab, Chrome reloaded it, and it resumed working properly), etc.