So far, so good.  It does what it's supposed to do.  Doesn't seem any faster or slower than any other micro SD card I had.  Bought a cheap imitation on Ebay and regretted it as it crashed.  It really doesn't pay to be cheap with memory.  It's all about the reliability, which you get with this product.10/17 Update:  Big problem with this SD card if you are a Windows Phone user - does not properly record HD video.  Video recording to SD card is consistently choppy.  Pop in another SD card - records fine.  Record to my phone - records fine.  I've tried formatting it every which way and it isn't working well.  Go with another brand Windows Phone users.