memory footprint or not, chrome is faster than firefox. both in terms of page loading, and raw operation. i might reconsider firefox when it doesn't take 4 times longer to boot up.
I am on Firefox 5 and I don't see visible differences between them anymore. Yes, Firefox 3.x used to be visibly slower.
I also don't see visible differences in boot time, but this depends a lot on how many extensions you have -- I only use Firebug and the Web Developer toolbar. And at least Firefox has plugins that aren't totally useless.
I think it depends on what hardware you're running. On my laptop Chrome is so noticeably better I only keep Firefox around for testing. On my maxed out desktop I can't tell the difference.
firefox 4 is visibly slower on a completely fresh install on my mbp. you may have a point about firefox 5, i haven't tried it. my firefox and chrome reference has only been the past to 2 years of major releases.
Starting up a browser is a relatively rare even, for me at least. The only time I restart Firefox is when it's consumed or leaked too much memory, about once a day.
I also don't see visible differences in boot time, but this depends a lot on how many extensions you have -- I only use Firebug and the Web Developer toolbar. And at least Firefox has plugins that aren't totally useless.