to be honest I think they only release all these name changes to get publicity
We all know they could just stopped this number inflation at the begining of 2011 ( 9.0.597 released 2011-02-03 yes 7 months ago ) and gone from version 9.0.597 to 9.1 to 9.2 etc etc but that doesn't get them any publicity. however eventually these number changes are going to start looking silly and they will probably switch to silly words and work through the alphabet like andriod and unbuntu.
I only got chrome for angry birds anyway. I don't notice any worthwhile speed differences so I use IE as I like the accelerators feature and its easy to adjust the page zoom with a mouse ( with no macros ).
some sites do work better with chrome but too few for me to switch from using IE as my main browser. It's not just speed that makes a browser good its features ( sometimes just one killer feature is enough) , customizabilty, flexability, add-ons, and something you enjoy working with. All these together make a great browser.