Fullscreen apps work great on a Macbook, and you only need to know two simple trackpad gestures: three fingers side to side, and three fingers up. And yes, you can break out of it by mashing ESC.
It's an interface clearly designed for a multi-touch trackpad, and it's a joy to use. It makes a 13" laptop screen feel a lot less cramped. Contrast to Win8 which is an overcomplicated mess, filled with interface decisions that are suboptimal for a mouse or trackpad interface.
Especially with the low screen resolution of the 11" MacBook Air, full-screen mode becomes essential. On a 27" 1440p display, not so much. I personally use full screen mode for iTunes (mainly so that iTunes is always a quick multi-swipe away) but not for anything else.
I think the animations on Mac OS make full screen mode great. Slide some fingers on the trackpad and you switch to the next full screen app or virtual desktop. On Win8 it's a jarring zoom in zoom out animation, without any ability to 'peek', at least using a mouse/keyboard interface on a desktop.
I actually quite like OS X fullscreening on my 15" rMBP. I usually keyboard back and forth between apps instead...I can never quite get the three finger swipes working reliably. It even works pretty well with multiple desktops.
But until Mavericks, it was horribly horribly broken and useless on multi-monitor setups and even now isn't all that great.
It's an interface clearly designed for a multi-touch trackpad, and it's a joy to use. It makes a 13" laptop screen feel a lot less cramped. Contrast to Win8 which is an overcomplicated mess, filled with interface decisions that are suboptimal for a mouse or trackpad interface.