Skate Sizing: Bauer vs CCM

[estogoalie]

My son is using Bauer Reactor skates (4000 or 6000, I forgot). Anyway, he likes them, but when he plays 2x a day for several days (eg. training camps) he gets some red marks on his heels from his foot sliding up/down. He tried on some CCM Ribcor with the pump, and he liked them in general, but they didn't have the right size. He wears a 10 D in Reactor, and it looked to me like the sizes run similar on CCM? And is there any real difference between D and EE on the Ribcor?