Excerpt: This works with my Samsung NX1 to shoot 4K 30fps videos and RAW Burst Photos, nothing unexpected here. It's a bit pricy obviously but you get what you pay for so if you need high speed UHS-I, this is it. Side-note, you probably don't even need that speed to shoot 4K with the NX1 since it's using H265 codec, but who knows if Samsung will release a firmware update that would allow you to shoot at higher bitrates in the future so this is definitely future-proof.
Excerpt: I bought the 64 GB Extreme Pro UHS-I SDXC U3 card for use in a Panasonic Lumix GH4 shooting Cinema 4K video. The card is fine and has worked flawlessly in the two weeks or so that I have been using it. It would be helpful if Panasonic, SanDisk, or B&H could make a SDXC card chooser app because although I knew that I need U3 card for the 4K video, there are a number of options and I am not quite sure exactly which card I needed. Why 4 stars and not 5 stars?
Pros: Large Capacity, Reliable Performance, Writes/Reads fast
Excerpt: Bought this for my Gopro hero 4 Black. Seems to be working great so far. I did struggle figuring out if I had the right card or not. The picture is totally wrong on the web site. It shows a U1 card. I got the U3 like the add stated so I was only slightly annoyed. It would have been 5 stars if not for the adds picture being confusing.