Sizing Miura and Katana?

I wear an 8.5 wms street shoe and am wondering what size to get. I had the w katana and downsized to a 37.5 (6.5) which worked really well, but were always painful. Do the sizes in both shoes run the same? I want to get a half size bigger in the miuras so they're a touch more comfortable, but fear they'll be really sloppy bc they're more down-turned (different more agressive last).
Suggestions?

Tech Specs:

Material:

Leather upper 

Lining:

Dentex 

Sole:

Vibram XSV 

Last:

Slip 

Asymmetrical Curvature:

Yes 

Lacing:

Standard 

Optimal Use:

Rock climbing with technical footwork 

Weight:

19oz 

Warranty:

Lifetime 

Country of Origin:

Bahrain