I haven't used Sublime Text but I know it's supposed to be all the rage plus it's $70 for full version. I have used Atom a bit on my Linux machine when I don't want to use Vim. Atom has never given me any problems, though I haven't forced myself to learn the hotkeys or other special controls yet because frankly, I'm burned out after learning Emacs, Vim, Visual Studio, and Visual Studio Code.
However, IMO, speed shouldn't be a concern for an editor, especially speed of startup. I mean, do you plan on starting your editor 5,000x a day? I never understood the speed argument unless it is literally lagging to the point where it is not responsive for user input or creating new tabs, etc (which Atom has been fine with in my experience). I don't know anyone who goes home at the end of the day sad because their editor couldn't keep up with their typing speed! It's usually because they had to go to another ridiculous meeting!