There's a lot to like about the new editors, but it's a pretty big tradeoff, IMHO. Even on reasonable-sized files, I notice the speed difference, and sometimes Atom or VS Code do something pathological and end up making me wait an inordinate amount of time for it to sort itself out.
Also, Atom has improved quite a bit. It used to be remarkably slower than VS Code, and now it seems to be only marginally slower (though both are among the slowest in this bunch of tests, so it's faint praise to say Atom is "almost as fast as VS Code"). Nonetheless, Moore's law has given us a world in which even very, very, slow editors are Fast Enough(tm) for most of the work, most of the time.