Can confirm, I tried using Atom for four months but recently gave up.

Electron and other Chromium wrappers are the new client-side JVM.

Shame to hear that, I had hoped things had improved a lot. I tried it early on, then tried to open something like a 100M file and it threw an error about loading "large files".

Why? Speed?

Visual Studio Code is based on JavaScript too and it's very fast. They even both use Electron, the JS-desktop-app core that the Atom guys open sourced separately.

VS Code is leagues better than Atom, but it's still perceivably and annoyingly slower than Sublime.

Especially when dealing with large files, atom just breaks. In ST3 it shows loading the file, but never becomes unresponsive

I'm not even talking about large files -- I'm only talking about normal interactions on small (1-10KB) files. Moving the cursor around in the text field, especially when my language plugin is in some mode that has some dialog up on the screen. Find and replace. Switching between open files. All of these operations often (but not always) demonstrate noticeable lag between keyboard input and screen output in VS Code (and Atom, of course).

Doesn't this look more like an un-optimized edge case than anything else?

Loading a 100MB text file is not really common, even among developers. Only logs and DB dumps are really that big.

I can't seem to open files of 1MB properly in Atom. Also I find it very useful to open logs to find-replace some info from logs.