I agree with you on that note! Horrible internal border sizes where everything Win10 related is rather slim and streamlined, styles removed not allowing borders to be thin makes this the most horrible looking update, even for those who leave the windows maximized! It's really ugly in my opinion...

Here's a side-by-side comparison, look at the ugly thick frames between the channel and nicklist, and the editboxes, and oh my god, don't even enable the command box! With the exterior having such a thin border it doesn't even work with the windows 10 theme, having borders on all sides BUT the bottom makes it even more off-putting.

[Linked Image from i.ibb.co]

I too will be reverting until there's more visual adjustment added back to remove the uglyness.