There are Chrome extensions if you want to change the color of the background.
The quoting is awesome. If you highlight part of the text a 'quote' icon pops up. This makes it a lot easier to quote! Additionally, things that I like:
Editing features, such as bold, italics, bulllets etc.
Recent posts across the complete forum (this works again)
Mobile accessibility - no longer have to zoom in and out constantly to navigate
I think overall the new features outweigh the appearance. Obviously, there are things to be ironed out, but that's typical of any software related releases, think new iPhones. Overall, just played around for a few minutes and think it works pretty well.