There isn't a club out there that would want Theo as more than a sub. He doesn't yet realize how good he has it at Arsenal, and should see how the England NT uses him. That's how he will end up if he goes to Chelsea or City. The next SWP, Adam Johnson, or Sinclair.
What angers me the most about his departure is the media shitstorm that will erupt, and the fact that we won't replace him with quality. If we had gotten someone like Jesus Navas or Younes Belhanda, nobody would care about him leaving. Instead we'll probably replace him with another young pace merchant, like Ryo -- who will probably become the better player (someday), but will take time to.