Def need to pick up the Mastermind XR1s tomorrow, but I'm not sure about the sizing - never had NMDs before.
My Nike TTS is a US 8. The uncaged UBs were to big for me in a regular 8 so I got them in a womens US 8 1/2 (which is a EUR 40 2/3) and they fit perfectly. I figure a mens 7.5 would fit...