Personally I hate when editors try and make my markdown look like anything but plain text. Syntax highlighting is fine, but I don't want you to make my font bigger when I type # and I don't want my text to be italicized when I type an asterisk, etc. Plain text has a purity and simplicity to it, and if I wanted those features I would probably just use MS Word or Pages or something.

I don't personally find the preview to be distracting, and I like seeing the rendered product with a distinct separation from the code that generates it.

I don't think I'll swap to this since I'm relatively happy with just having MacOS preview and a terminal in a workspace split, but I could totally see why someone would like this.