Not related to the eos-m camera necessarily but I have a comment/question...
I have a PNY pro-elite 32gb class 10 @ 35mb/s. it's good when 50%> full. When its even around 50% full, I find the card to slow down significantly. Very very annoying in many situations. Is that normal? Sandisk extremes better? And I think that it's better to shoot photos in smaller sized cards. Largest I'd use is 16gb. 8's are good! Now for videos, of course you'll need larger cards (32-64gb).
5D3, SL1, EOS M, 28mm f1.8, 10-22mm f3.5-4.5, 60mm f2.8, 40mm f2.8, 85mm f1.8, 300mm F4 L IS, 70-200mm F4 L IS, 24-105mm F4 L IS USM, 50mm f1.8 STM, 14mm f2.8 Samyang, Sigma 150-600mm C, 430 EX II, eos m lenses, bags and too much lighting equipment.