I bought this card after trying many others varying from class 4 to class 10. This has turned out to be by far the best 32GB I've ever used. The read speeds are awesome (23mb/s) and the write speed is around 9mb/s, so its a class 6 card performing like a class 10. The random read/write speeds are awesome on this card, this is very important for phones.
I highly recommend getting this card over any other ones, I was looking at the samsung class 10 which is £2 cheaper atm, personally I prefer Sandisk, highly reliable, lifetime warranty etc. I've had 4 samsung cards die on me, this includes the Extreme plus version.
Here's a link to test I ran using crystal mark.
Great service as usual from Amazon.
Edit: looks like the link I posted showing a screenshot of Crystalmark has been removed.
Seq Read 23mb/s Write 9mb/s
512K Read 23.15mb/s Write 3.73mb/s
4K Read 7.52mb/s Write 4.40mb/s
4KQD32 Read 7.61mb/s Write 2.16mb/s
50mb, ran 5 times.