Some have asked if it made a difference in a fast card or a slow card. I have an example of the difference. I recently purchased a very inexpensive dash cam for my van. Something that cheap should not even work, but it works very well. I put in my 16Gb class 4 micro SD card in the dash camera and on my next drive to town, recorded the trip. Did the same with a class 10 card. Video camera set to 720P the class 10 video was just as smooth as it could be. The class 4 card, the video has a pause about every 1-1/4 to 1-1/2 seconds. It is an instant stop and start and can be seen. Checking the video in a program where I can slow it down to almost nothing, the amount of the picture that is lost can then be seen. Not much, but that jerk looking at it is annoying. So who watches videos of their trip to town, well, no one, I would think. Only done to check out the recording device. It will be useful if some event takes place in front of my van. The faster card might just make your video and pictures from your quad better.