We're still stuck on 2005 at work (hopefully migrating to 2014 in late summer) so I've not had the joy of playing with Extended Events in a production environment but it always scares the hell out of me when old tried'n'true methods are replaced because they seem to always leave something out. Things like the {f4} key in old Query Analyzer didn't make it into SSMS and it was some really helpful and easy to use functionality when you really needed it.