This is an interesting change! Having used it to write some longer posts today, the main thing I am having trouble getting used to is that the left side takes up more space than the right side, which means that the two sides quickly get out of alignment.
I’ve gotten so used to watching the preview as I write to confirm that it looks like I want it to, to the point that even after all these years I STILL sometimes click on the preview side instead of the markdown side!
With this change, that will of course no longer be a problem. It’s quite clear where I should be typing.
Will have to give this some time to get used to it, but I do think I agree with @schneeland that the markdown font could be smaller.
