I spent the past few days with Google Chrome for Mac as my default browser on my primary machine. I tweeted some notes about the experience if you're interested in the details.
I've reverted my default back to Firefox (3.6) however because of page incompatibility (rendering, JS execution, and lacking plugin support) issues I just don't have time to workaround with a new browser.
What I did like about the experience however were the DNS pre-caching optimizations that Google incorporated, and how child-tabs were handled; nice work!
Building a browser is hard. Good luck Google.