I use Start 8 instead of Classic Shell due to having random issues with Classic Shell .
I would however suggest not going with 8.1 at the moment due to the mouse lag issues - they are fixed for some people with this patch: http://support.microsoft.com/kb/2908279
But it did not fix my issues so back to v8 I went. Also there are issues with TeamViewer and v8/v8.1 and certain games going fullscreen.
They don't exist in v7. At the moment I prefer the theming in v8, so I just shutdown TeamViewer when I play some games. I occasionally forget to restart it though and then when I try to access my home PC ... fun times.