Order 1/2 size down.
I have owned, oh, about 100 discrete Nike shoes in my life (i.e. not counting duplicates of the same model). Almost all have been size 10.5.
The first generation of courtballistec ever made: I had to order a 10, which was consistent with Tennis Warehouse's recommendation.
The Air Max Cages - the right size is 10.5, per Tennis Warehouse's recommendation.
A note: nominally my feet are odd-sized, so occasionally I buy two pairs of shoes so that I have a 10.5 for my right, and a 10 for my left. So objectively, I am able to place my size 10 Cages next to both a 10 and 10.5 2K12 shoe. Objectively, the physical length of the 10 Cage is the same as the 10 2K12.
So why did I size down? It's not necessarily about the physical length of the shoe, but the last and the shape. The toebox of the 2K12 is longer and more tapered than the Cage. Therefore there is length in the shoe that isn't occupied by your foot...this is somewhat hard to describe. The toebox of the new cage is more rounded in the front and wider.
Bottom line, as a general rule, I agree with TW's recommendation to wear a half-size smaller than what you typically wear in Nike shoes.