Tom,
I use a Class 10 micro in mine. I don't remember the brand, but I bought it for cheap at MicroCenter. I use 60 fps at 1080p as well. I have found that if I copy them to my computer and use VLC player which is my machine default for all media except audio, it is very jittery and jumpy. After some research, I found many others posting the same thing, and the conclusion was it is VLC's codec (which is usually flawless for everything) and it's addressing DX or OpenGL. They recommended using Windows Media Player (which i previously used only for audio files) and it looks great. Also make sure you get on GoPro's website and get the newest firmware update for the cam.