So, yeah, I’ve now tried it, and while it does in fact do exactly what I was looking for on singe-site installations, it does not work for multi-site (http://wordpress.org/support/topic/multisite-110), which is what I have for this site…

Well, some things do work (like the syntax-coloring in the post editor), the important part for this article (being able to edit JS files), does not… :-(

But, yes, for single-site, totally something I would recommend!

Thanks for the recommendation,
Atg