Being able to step outside software engineering when engineering software.
'Perspective' ...
Mini perspective: step away from the desk, do something literally creative. I play my guitar.
Major perspective: get the hell out of the city, actually do something on a weekend. Come back - all of a sudden you have fresh eyes and see things more clearly.
I actually think that soft devs should take more vacation.
You know that professional concert musicians only practice a few hours a day - any more is pointless. You just can't concentrate that long.
A really gutsy move would be for Google to give a bunch of 'long weekends' where nobody can work, or even more vacation. And see what the results are.
I find when my brain starts to grind to a halt I just go an do another un-related task to force myself to completely forget about the original task. It does help because when I go back to the original task my brain has to context-switch back into it and in doing so it may look at the problem a different way.
Extra holidays would be great! However, I think more holidays would make some engineers more productive and some less productive... I'm not sure if Google is still doing their 20% time, and if they are I know it doesn't apply to all the FTE engineers.