So I bought 3 128GB Samsung cards, two were bought from Amazon, and I made sure direct from Amazon, and one direct from Samsung. One of the cards is older, don't know when I bought it but it was about 6 months before the other two, I got it from Amazon. When I got my Gopro 5 I ordered another 128GB card from Amazon and then got an email from Samsung for $10 off at their online store. I went to their store and noticed all their cards were about $20 more than what they were on Amazon so even with the discount I was paying $10 more but I got one anyway as Amazon didn't have the exact card I wanted. So, the old one still works but isn't anywhere near the advertised speed, the newer one from Amazon wasn't either and sometimes my Gopro would just stop recording with it. The one I got direct from Samsung was the same as the second one from Amazon but an upgrade from the old one I had and it exceeded the speeds it was advertised for and my Gopro hasn't had a problem with it. So, the old one is still working, but like I said isn't as fast. The second one from Amazon died finally and I didn't use it nearly as the one I got direct from Samsung as it just didn't' transfer as quickly. For an extra $20 bucks it is worth it to get a card that is the correct advertised speed and a little more assurance it won't die. I think the first two were either counterfit or Samsung keeps the best stock to sell itself, I don't know but I don't think I'll get memory unless it is direct from the manufacturer. With cards getting so large it isn't like anyone needs 20 cards anymore anyway. 3 was way too many cards at 128GB for a Gopro and two is kinda stretching it but it is nice to have a backup. Anyone else just by direct for the manufacture when it comes to SD cards?