One of the biggest frustrations for me with my new HTC M8 has been SD cards.
All of my usual cards I use in various devices have all been too slow for Zoe so I invested in a Class 10 32GB. Get the same warning 'To enjoy a better Zoe experience, please use a higher class SD card' or a message very similar.
I've also had a few times when my SD card has become corrupt at various times.
Am I alone in experiencing these problems?