Oh, wait, I just figured out part of it. In Jetbrains products, I am CONSTANTLY hitting Esc to Tab to deal with the helpful predictive suggestion. I find that

Oh, wait, I just figured out part of it. In Jetbrains products, I am CONSTANTLY hitting Esc to Tab to deal with the helpful predictive suggestion. I find that feature sometimes useful, so I have not turned it off. But it definitely produces a different and maybe slower experience than typing in emacs. Maybe there is a mental mode switch between typing and handling the hint?