Just curious: how many folks can accurately touch-type the Fn-keys? Personally they're too far away from the home row for me to hit accurately, but maybe that's because I use too many different keyboards and they're all slightly different with spacing. The esc key is easy with it being located in the corner, though. So in my case, I would already look down to hit an F-key, and I imagine functionality such as "compile…
Honestly, I've always felt that Fn keys were an outdated and faulty design. They're too far away to reach gracefully, usually offset from the standard zig-zag of other keys, and awkwardly multi-roled with screen/sound options on most keyboards.
If I'm in an IDE that uses a function key for something like 'compile', I usually rebind it for my own sanity. I have mixed feelings about this update (contextual buttons are often terrible, and I don't mind escape), but losing Fn won't really matter.