J. Van Wagenen
I had been using a 'regular' SanDisk 32GB Micro SD card that came included with my HTC Thunderbolt I bought in 2011. The size was decent, but I never realized until upgrading how much I was lacking on the speed.I finally got one of these to replace my old card with my Galaxy S3. It is superb. I just recently got a Galaxy S4, and again, this card is just about the best expansion you can add to most any phone.With my old MicroSD card, I had gotten used to just sitting there, zoning out, as I waited patiently for my computer to transfer pictures/videos off my card to be backed-up to my PC's hard drive, or copying some music files from my PC to my card. With this new card, almost any single file (even hundreds of megabytes big) is an instant transfer, that transfers too quick to even bring up that &#34;moving&#34; dialog box in Windows 8. On my very big transfers (lots of HD video files at once, totaling several gigabytes), I have to wait, but I'm waiting for seconds instead of minutes.Combine the excellent speed with the fact that 64GB can hold a ton of data (compared to typical storage sizes on phones), and you have a very satisfied customer. Now I can procrastinate even longer the occasional transfers of all my pictures and videos to my PC, though I try not to.A lot of phones (like my S4) specify 64GB SDXC cards as the maximum they support, so this is about the best you can even get for the moment, unless you want to pay almost double for SanDisk's Extreme cards. Unless you have money to burn, I think these are a much better value and diminishing returns certainly kick in beyond this price point. But perhaps my next phone will support 4K HD video onto 256GB cards and I will yet again need to upgrade my card's capacity and speed... Anyway, bottom line on this product: AWESOME.