I have Yosemite GM-3 installed... when I go to the app store, it says "You already have Yosemite installed" - Should I care or try to reinstall from the "final" installer?

Also, my biggest frustration has been the workflow change of the "maximize" button to it's new role as full-screen button. I wish there was at least a config option to switch it back. I'm fine with adding it as an option, but completely breaking the workflow seems unnecessary IMHO. I guess that's why I use "Spectacles" app for window placement keyboard shortcuts.