It's been a couple weeks now and I'm really thrilled at my switch to fullscreen mode on my Macbook Air. Any application that supports it I now run in fullscreen. The change in my daily work has been incredible.
Terminal.app in fullscreen is a beautiful thing. To me there is something pure about a shell. A shell in fullscreen? Breathtaking. Throw screen into the mix and it's nothing short of masterpiece.
Mail.app is great too. Composing a new email is an uninterruptible single-window with the message you're preparing providing little opportunity for distraction. The other bonus is I'm no longer leaving emails opened in background windows accumulating dust. Instead, I flag messages which require a reply, which is clearly displayed as a count. Being OCD, unread counts drive me nuts so there is an added incentive to reply to flagged messages quickly to keep the folder count down.
iCal feels better but that may also be to changing to a daily view, rather than a weekly view. It allows me to keep my attention on the day rather thinking about my schedule for the rest of the week. I do still cringe at the animations bouncing between days/weeks/months as it just delays me getting the information I'm after. (Thank you interwebs! Apparently cmd-arrow disables the animation.)
My other favorite apps, Numbers, Reeder, and Sublime Text all look fantastic. They adapt really well to the fullscreen approach.
I'm split on Chrome. Some things are just great, but others (like the menubar dropping down for new tab creation) are just plain annoying.
Overall though this has really changed my daily work in really great ways. Having upgraded my Macbook Air to run Mountain Lion, the addition of the Notification Center and Reminders.app will be interesting in the mix.