I would say go with the Vapor size... although, it depends on which pair of 2K10s you're getting.
The earlier colors were true to size (white, grey). But then the more recent ones are bigger and I went down half a size (photo blue). And I went down half-size in the Vapor 7s and 8s, too. But stayed with my regular size in the CBs (all iterations).
If you're ordering online, just get both and return the one that doesn't fit.