Take your camera to the camera store and have them bring every 70-200 2.8 II out and try them in the store until you get happy. Don't leave until you get one.
Another lesson learned, if it ain't broke (as we say in TX), don't fix it. That old lens is looking better.
Anyway, picking an argument with Canon ( I had one originally with my copy about a year and a half ago) will be fruitless. To save you all the middle steps, here is what will happen. You will send it in at your expense a few times (shipping plus insurance), and have to be without the lens. Finally, after many letters and calls to low to mid level service reps, they will send you a refurb in exchange for your new lens. Save the ulcer. Some battles you just won't win.
Good luck with the lens
Aren't you the Lambo/Maserati poster?
I bought mine last year in october. I do not see this halo effect.
I would say that this person got a defective lens. Recommendation is to bring it back and exchange it.
..only that he has done that 3(!) times already...