* Top left corner: Show all four spaces in a 2x2 grid
* Top right corner: Show all current application windows
* Bottom right corner: Show desktop
* Bottom left corner: Show all windows
I've been using this setup (minus the Spaces part) since 10.3, and have yet to find a workflow I prefer for managing windows on a laptop screen's limited space when using a laptop with no external displays hooked up. I'd prefer to also have Leopard-and-before style proportionally-sized Expose to SL's grid, but that's a minor thing.
Lion's Full Screen Mode and Mission Control appear to have made things more "accessible" (and oh, are people often surprised by my setup when borrowing my laptop for a bit and inadvertently hitting a corner!) but I can't find any way to replicate what I had before. As far as I can tell, the options are just gone.
And I find the removal of features I'd come to love really disturbing, especially coupled with the move away from hardware upgradability/expandability.
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As far as moving the Mac to ARM goes... that's in all likelihood the day I buy another ThinkPad. And for pretty much exactly the same reasons as the first time, when my PowerPC-based PowerBook G4 just didn't have enough power, and couldn't virtualize x86 OSes for testing/dabbling/whatever.