http://us.battle.net/wow/en/ This game was written with TCP as was http://www.guildwars.com/ . Also http://en.wikipedia.org/wiki/Warcraft_III:_Reign_of_Chaos and the http://www.ageofempires.com/ series.
All in TCP, where as WebSocket is built on TCP it can create a more raw steam of data. So it's possible for better results.
However, let Scirra get more important stuff done :D I would like to see sharable packs of EventSheets and associated objects :D