I've watched almost every game (including having the final group games on two screens), and I've enjoyed it a lot, but after beginning with a bang I think there have been quite a lot of relatively dull games. Rated against other major tournaments it would be below average for me so far, but who knows the knock outs could be brilliant.
I think the best thing has been the atmospheres in the matches, which have mostly been brilliant, though dampened a bit by the amount of bottle throwing that seems to have crept in.