I'd pick the all-caps (albeit a bit 'shouty') `CTRL+Q` the big guys seem to stick with this convention e.g. [Keyboard Shortcuts for Windows](http://support.microsoft.com/kb/126449)

I *do* think it's easier to read and because of *everything* being uppercased, less confusing on the 'shift' key or not.

And for those that are still confused.... Trial and Error!