I couldn't care less about the Caps Lock. I rarely use it, but it doesn't bother me.
My frustration is when I use different keyboards, and the Home, End, PgUp, PgDown, and Delete keys are in different places, or are shaped differently (double height delete key, for example). The same goes for arrow keys.
I use the HELL out of the Right Click Context key on my keyboard. I've noticed that Logitech has been replacing that key with a FN key to switch the purpose of F1-F12 to other stupid things no one cares about.
I also use the crap out of the Windows key to start searches or enter UNC paths to get to network resources quickly. Though if it wasn't there, I would learn and use it's alternative shortcut key.