Szu-Ping Leewrote a review of Tenaya Masai Climbing Shoe on June 3, 2016
Familiarity: I've put it through the wringer
Fit: True to size
I have asymmetric foot shape (big toe about the same length as the second toe), and slightly wide. The front part of the shoe fits great. All the praises about its edging ability is correct. My toes are together and powerful, there is no dead space at the front. It is also comfortable, I can wear them for 2 hours before my left foot start to get a little sore around the big toe. I think it stretches about 1/4 to 1/2 size.
The problem for me is the heel shape; there is a large air pocket in that area which hinders heel hooking ability. I consider my heels pretty normal, but this shoe is designed for those with large calcaneal protrusion.
The material doesn't breathe well so I often have sweaty feet, which is something I have not experienced in other shoes (Scarpa Thunder, Evolv Astroman and Shaman). Initially the heel band (the rubber rand that pushes just below the Achilles tendon) was a little tight, but it is now okay after about 2 months of climbing 2-3 times a week.
Sizing: if the heel fits, I think a 11.5 will work best. But because of the tightness of the heel rand, it needs to be a 12 for me. My other shoes sizes are: Scarpa Thunder and Evolv Shaman US12, Astroman US13.