Speed:
Faster than IE and firefox on many sites (especially Google products like gmail of course)

Usability:
super simple and easy, no search box is cool

New V8 javascript engine:
each page is a separate application so if a page crashes, only that page crashes, not the entire browser

Disadvantages I have found:

Javascript errors: obviously most sites are built for firefox and IE and when looking at sites that maybe did not take Chrome into consideration during their beta testing some functions may not work

Flash Video: the first version of Chrome is picky when it comes to flash video. Depending on the site of course and video player type.

New V8 javascript engine: this engine does have it’s bugs and the entire browser has crashed on me