MacSpeedZone posted a speed comparison between browsers:
"On most performance tests Communicator 4.7.3 and iCab won the speed test. Internet Explorer was not that far behind and in the Java test it blew the Netscape away."
This really comes from the "who cares" department except for those really hardcore users... as the extra second saved at launch time or page rendering probably won't affect your life... but there is a good comparison chart with system requirements and resource usage.