Been using Chrome beta for some time now on Linux, still have to use Firefox for most stuff though as the plugins have proven to be a bit buggy. I haven't downloaded Opera 10.5 alpha-beta-oh-la-la yet. I usually get ticked off at Firefox for something then end up switching to Opera for a few months, then I get ticked at Opera and switch back. Its vicious cycle.
FF 3.6 is my default now though, and will be into the foreseeable future. Really, if I have to think about my browser, its not doing its job. IMHO