"2 out of 5 cards defective so far..."

I ordered these cards at a great price during black friday week/weekend. I began loading some files (music, videos, pics, etc). The first card worked without any problems. The second card started giving me cyclic redundancy errors. At first, I thought it was my hard drive that was failing, and tried to copy the same files to a flash drive which worked just fine. Ok, maybe I received a dud, and tried with another card from my purchase. Same results, cyclic redundancy error. I started searching online, and found a utility via one of the reviews on Amazon called H2testw. Ran the test on both cards, and it reported errors. It also reported write speed of only 4MB/sec, which is way below advertised speeds. These items were in retail packaging, and I remember reading about the bulk package items being fakes. I guess the retail package cards aren't any better.I should have waited to do the refund because now I have to process the refund seperately. I will test another card to see if I have better luck. I wanted to leave a 1 star, but I gave 2 stars since 1 card worked so far. I have 2 more to test.Very dissapointed because I was a fan of the Sandisk Ultra series for being reliable, but I guess they are cheaping out on quality to increase their profit. I would have been extremely upset if I used these cards for anything important.

"perfect"

What else to say about this Sandisk Ultra 64 GB micro SD XC ? just perfect as all Sandisk cards