To put it in short, if you use firefox, chrome, safari, or opera..or anything else..your less likely to get viruses, malware, trojans or have your computer hacked or identity stolen. Your also less likely to have said malware or Trojans obtain escalated privileges or have the same impact as they would.
Your also less likely to have any issues with sites, even little small issues. I have worked with people for a long time on technical issues only to find out they are using Internet Explorer and then upon switching their problem is immediately resolved.