Bloat? The underlying OS takes up more HDD space, but as far as memory usage is concerned—and that's what matters when it comes to OS speed—it's slimmer than Windows 7 was, even with the new WinRT API constantly running.
As for Classic Shell... meh, I had issues with it. Minor issues, involving performance and sometimes staying open when I clicked out of it, but enough that it was really annoying to me. I get the same trick done with
Start8. It's not free ($4.99 USD), but it feels just like native in a way Classic Shell didn't quite manage.