One thing I've found strange about Chrome's DNS cache is how quickly items expire from it, they're gone within a minute or so. I know Firefox is changing how they look up DNS stuff (more in line with Chrome) by skipping the OS resolver entirely, and using something like unbound for DNSSEC validation (And hopefully bypassing the OS X issue that causes it to randomly disable IPv6 connections for a host)
Well, the major problem I have with it, is when I need to edit my hosts file to point to a specific server for any particular website (which I do often as I work in clustered environments). I have to quit Firefox and restart it before any hosts changes take effect. Usually I just use Safari at this point.