The first thing you must keep in mind is that Chrome is not finished yet, far from it by the way. Google is putting great efforts in building the world's best browser but so far they are only working in the tip of the iceberg. Google Chrome is fast, light and works perfectly with all Google products except Google Desktop which doesn't even run at all. Is Google Desktop getting worse all the time with all these new codes and software or it's just me computer?

The first big mistake of Chrome is making people unable to search the bookmarks like we can do in Firefox. We have to manually scroll them down all one by one and when you have thousands of bookmarks it's just not practical. Firefox on the other hand searches all the bookmars in real time in a side bar inside the browser so you don't have to leave the page you are on and that makes surfing between tabs fast like lightening.
Another huge problem of Google Chrome is you don't get a warn when you are downloading something and you close the browser by mistake. Google just stops the download and if you want to resume it you have to go to the website again and start downloading it again from the very beginning. To make this issue even worse, you can't open a closed window from the recently closed windows like you can with Firefox so you you close anything and you want it back again, good luck searching for it in the history.
Google Chrome does not support extensions like Firefox does! This is a critical issue for all the people that depend on extensions to work faster and better. Google must take care of this as fast as they can or they risk user interest loss...
Chrome options are still very incomplete. All you can do is to tell the browser whether you want your passwords stored or not and some other minor tweaks... Firefox on the other hand has a huge portfolio of options you can change at your will.
If you are decising which browser you should take with you all the time, Firefox is the ONLY choice now more than ever for all the cool features and extensions people keep adding all the time.