“We can learn from the competition,” said Dotzler. “The way they implemented multi-process is RAM-intensive, it can get out of hand. We are learning from them and building an architecture that doesn’t eat all your RAM.” That's the money quote here. I've been waiting for this for a long time actually. Every browser I've tried except Firefox just basically eats all my RAM and other app performance (e.g. compiling stuff…
If you're on Mac, Safari is good in terms of both memory and cpu.
Firefox is my favorite browser overall (especially on other OSes), considering its smaller memory footprint and lack of sluggishness with tons of tabs (compared to Chrome) and the fact that it's from Mozilla, a company I hugely respect and admire (even with some of the missteps that have happened in some aspects in the past few years).