I have upgraded to sitecore 8 and facing critical issues regarding only the Experience Editor.
After logging into Experience editor with Admin rights, the page opens only with one tab "Optimization"; no buttons are active though.
Also, i found one issue that i was familiar with:clicking any web edit button would add a "#" symbol at the end of the url. This behavior was found when i was developing a javascript and debugging it and whenever there would be any error in js, "#" would get suffixed to url and button click wouldnt work.
I am not sure if this related to SPEAK features and how to tackle this issue with Experience Editor ?!