My experience with the Eject shoes has been to size down, or rather, follow the European sizes.
My foot is an 8.5W and in most brands I can wear an 8.5 or 9. In Eject, I wear a 39 EU, which Amazon translates as a US 8.
If you're a 7.5 I'd go with the 38 EU/US 7. You can also buy from Endless (at a higher price) for free shipping/returns.
See, no excuses now.
MNSara and Alaskagirl, I must know which ones you're eyeing.