There's actually a lot to be said for having organizations host important events either back-to-back or more than once. Have heard Barcelona did such an amazing job and the second year was even better. The same could be said for Boston - after having hosted a very important Olympic year US Nationals, they truly delivered with Worlds in Boston 2 years later. So much depends on organization and volunteers, and when the wheel has been 'invented' ... why not roll with it more strongly once again!?