Look at this screenshot. I have 12 tabs open, and the total memory used is only 245MB. Firefox has always treated me good, but towards the end it would be over 300MB not long after opening the browser. If I had 12 tabs open it would probably be 10x what Chrome is using.
And no "hott notes" is not porn. It's a cool little post it note program that is always running. And no, not downloading any movies from a warez site there, just doing some research was all.