1. The response from the shell is lightning. It is very quick. Once you log into the shell, the responses to mouse clicks and keyboard short cuts is amazing.
2. Installation of extensions is now childs play with Gnome 3.2.2. It is as easy as 1-2-3. GO to https://extensions.gnome.org/ and click on your favorite extension. On this page and to the left of the title of the extension you have an ON/OFF switch. Just slide the button to ON and accept to install the extension in the pop up dialog. Thats it!!. The extension is installed. Repeat this step for all the extensions you would like to install. Then log out and re-login. You should be now running all the extensions you have installed. As a guide for the best extensions, I would point you to http://justinstories.wordpress.com/2012/01/29/five-most-downloaded-extensions-of-awesome-gnome-shell/
Thanx to the G3 devs for acknowledging the requirement of the community and supporting the extensions within their main framework and many thanx to all the devs of the awesome G3 extensions.
PS: The user theme extension is somehow disabled for 3.2.2. As per the G3 website it will be available in 3.3 and later. I, for one will wait.