Zed was my daily driver for almost a year. When it's working fine and not drawing the mouse cursor at 3 FPS it feels pretty much as anything else in terms of perceived speed. I saw mentions that you need to be younger to notice the difference. Like you don't hear frequencies above 18 KHz if you're more than 20 years old. I get the idea, I just don't see where it is connected to my real world experience

As a quick anecdatum, I'm on macos and I'm definitely more than 20 years old, and there is a quite perceptible difference in responsiveness between Zed and a VSCode-based IDE for me. (Though then again I did play fast-twitched games a lot when I was younger.)