The only thing you can say about Tokyo, is that you can't define Tokyo. Whatever you like, you will find it there. Whether you want crowd or tranquility, teenage discos or jazz clubs, thrift stores or Hermès... everything's there.
Tokyo is often totally misrepresented as a hectic, bustling city. I found it to be one of the most relaxing cities I've ever visited. I've never been to a friendlier place. Cons: Maybe finding good, cheap restaurants amongst all the chains and shopping centres? It's certainly an expensive city.