First, don't immediately judge the trackpad. Give it a couple weeks first. If you've never used a trackpad on a Mac before, it deserves a chance first. Give this article a readthrough and try out the gestures it suggests.
I'm not going to tell you that the 2009 model of the MacBook Air is the best computer ever; rather, it's an early implementation of a concept that wasn't really perfected (if you'll allow me to go that far) with the newer models.
The idea of the MacBook Air is centered around a computer that doesn't "cost" you anything to take it everywhere; it will fit in your bag, briefcase, or backpack, and you won't even notice it's there until you need it and pull it out.
My favorite OS X feature is Mission Control. You can read more about it in this article.
yeah i think too that windows is shit. You can't have multiple full-screen app and/or desktop (but i think they added that with windows 10, im not sure), no mission control, no launchpad, the trackpads are shit and you can't put a magic mouse (yeah, i know it's apple, but it's really cool for productivity). I tried linux once when I downloaded steamOS. I liked it, it looks a lot like Mac os. Windows is like a retarded OS, people use it only because other people use it (more software, more people can help you with it...)
Mission Control (formerly expose) is the way OSX manages lots of windows and multiple desktops. See here: http://support.apple.com/kb/HT4689
The Windows 10 snapping improvements are similar to the way Mission Control displays windows