Summary: Several months ago, I wrote a review stating that I rated this was an impeccable product. That sentiment has since changed. I indeed did purchase two of these. I have found that they are prone to failure and are significantly flawed devices. They also provide no indication of their impending failure until you realize they cannot be written to or the file system becomes corrupt.
Pros: High Capacity Fast real-world performance speeds Comes pre-formatted out the box in exFAT format which avoids the file-size limitation of FAT32 and offers maximum compatibility with most operating systems and devices.
Cons: Poor manufacturing process Prone to file system corruption requiring reformat Prone to complete device failure.
Summary: Not sure if this is a phone/OS thing or a thing w/ this card, to be honest.
Pros: Excellent price, tons of space
Cons: WP8 supposedly supports this SD format, but when I tried to take lots of pictures in succession or take a 1min+ 1080p video, the camera would lock up and the card would wind up corrupted. I'd have to put it in a Windows PC, "repair" the disk, then put it back in the phone. I tried a (very) old 2gb MicroSD from SanDisk and it worked w/o issue in the same phone.
Summary: Going in the trash. Not even worth the rma. What a waste of money.
Pros: Good speed up and down
Cons: Used up about 3gigs then my phone stopped reading it. Got it to work again after about 2 hours of messing with it and it was empty. Lost everything on it. Formated and ran an sdcheck on it. Seemed good, week later about 3gigs bam lost everything again.
Summary: Given the many other comments on this card failing, I'm nervous about it failing and me losing my data when it does. As I said, this is a replacement for a DOA card that wouldn't work in anything. It may have been a 'great' price on Cyber Monday, but not if I lose my data... time will tell.
Pros: This is the replacement for the first DOA card. It seems to work OK (for now) in my HTC Evo 3D phone; I was able to copy my music on to it through the phone's interface/USB.
Cons: The card would not work (could not be read) using the SanDisk SD card adapter on a Win7 laptop. Windows kept saying it needed to be formatted, but formatting failed. I tried it in my phone anyway and it worked there... at least I can access the contents by mounting my phone as a disk.
Summary: I got it on sale, and at the sale price, it was a pretty good deal. Full price, it wouldn't be that great a value. Make sure your device supports SDXC cards and, preferably, ExFAT. Card comes in ExFAT format, but you can reformat it as FAT32 if your device doesn't support ExFAT. Windows won't create a FAT32 filesystem larger than 32GB but it can read one if your camera/Android/whatever formats it that way!
Pros: 64GB, "ultra" class card, exceeds class 10 speeds I use this for action shooting with my Nikon D5100, and the high speed of the card keeps the camera ready for continuous-mode shots. High capacity means I never have to worry about running out of space, and I can pop it in the camcorder for extended length video recording too.
Cons: Adapter did not work, either with this card or any others I happened to have. The actual micro SD card physically seems to be a little bigger than standard or maybe just has a rough edge, and it's hard to get it in and out of most card slots. It jammed in my card reader and I had to pry it out. Sanded it down a little and now it fits ok. Nobody else has mentioned this so maybe I just got unlucky with the fit & finish.
Summary: not sure of reliability as yet but no problems on that for the first week. In my transfer test I transferred a 300mb file on to the card. It varied in speeds from 4.5mb to 6.3mb but no better then that.
Pros: it works
Cons: slow compared to advertised speed. I have class 4's faster than this. Because of the advancement in tech this product is a bad rep for the newer XC's coming to say they are not a fast. This also does not work in most hardware because of the newer tech it is.
Excerpt: Needed a card that was fast and had plenty of space for raw photos. I've only used it a couple times for time-lapse and it keeps up with my 60D doing long exposures. However, when I import into LR4, only imports a few photos from the card and I get a message that some of the photos could not be read. If I eject the card and try to import it again, it works fine.