After a lot of testing between firefox and chrome, i had to settle for chrome atm.
- Both firefox and chrome were giving me problems with quicktime "plugin" playing videos (on gametrailers for example), firefox was crashing totaly needing a total restart of the browser, while chrome simply stated an error "this plugin is malfunctioning" and all the pages kept runing normaly.
- In therms of popups, chrome is doing a better job for me. It blocks most pop-ups, while firefox has a tendency to let a lot slip by.
- Firefox speed is basicaly a choice. You can make it faster if you dont have a lot of skins/addons, but thats the major advantage of firefox in therms of customizability, in this part i think chrome has a better speed/base functionality ratio, It feels much better looking (imho) than firefox with no skins/addons attached (for speed sake).
- Security wise, i can't quite judge as i never had problems with any of them (unlike IE).
All in all, chrome is working better for me atm, but i keep firefox updated to check it out as new versions come out, just in case, because in the end of the day, its also an excelent browser.