Three point harness
Three point car type harnesses seem to be becoming the norm on new aircraft. I know they are convenient and easy to use. Perhaps the passengers even feel more at home with them.
However having recently hit my head hard on the canopy its made me realise that they dont work. Great for restraining forward momentum perhaps, but useless for stopping you going up and down.
It is definitely not what you want for aeros (and fortunately they are never seen in aerobatic aircraft) but also not what you want in an instrument platform or anything that you might fly in more "severe" conditions.