Exactly. Once you know that it's actually preferable to Alt-Tab doing everything. If you are like me with sometimes dozens of open windows it's nice to have one more layer of abstraction.

I discovered this about a year ago and it vastly improved my general productivity. Definitely worth knowing. (btw, ` is the button above tab, at least on my macbook).

I don't want that though. I want to be able to alt-tab between my two most recent windows, without having to think about whether they're in the same application or not. It pisses me off that OS X (and Ubuntu now) has this two-level application switcher model, and I can't figure out how to go back.