Using Ctrl + * key combinations on ShionKeys improves efficiency by at least 30%. Because you don't have to move your entire hand to press Ctrl.
( Human engineering doesn't just make your muscles more comfortable.)
@ShionKeys [not serious, mostly joking] 30%… a nice round number. It must come from a very rigorous and reproducible benchmark ;)
You can have Ctrl on Spacebar on any regular keyboard with e.g. https://github.com/alols/xcape
XCape allows me to have ‘(’ ‘)’ on Left/Right Shift keys too. Any lisper will write code *30%* faster thanks to it and that improvement does not cost any money!