Just got my xbox this Friday and today I spent the day gaming. The load times and Quick Resume are an absolute game changer. Normally I play one game at a time and beat that and then move on to the next. I never thought to do it any other way because load times being what they were.
But being able to instantly swap had me enjoying The Medium, Control, and Star Wars Jedi Fallen Order rotating between all three today. When I would get a little bored with one, or stuck, or whatever I would instantly swap to another. And it was a really great experience. I constantly was able to change to match my mood of the moment. It's seamless. It was like swapping cartridges from the old days but even better because its faster than that to get to playing at the exact same spot.
I know this isn't new to anyone who's had the console since launch but I never expected to experience that.