Like @hnn in this thread, I’d like to be able to set “+10” into the X or Y coordinate, and have the selected objects move by that amount, even when they have different coordinates. @kcase responded that you can’t do that since “+10” would be a valid coordinate, which may be true, but unhelpful. This “just works” in Sketch, and I use it all the time.
Bug report: attempting to do this (adding +10 as a coordinate for multiple Groups) triggers a bug that I frequently see with Groups, where the Group size changes, as if it contains invisible objects. This is a non-Undoable bug. When this happens, you have to ungroup and regroup them. Screencast: http://recordit.co/gBTfNIWJWs