I have the Sandisk Ultra 64GB card installed since day 1, and it works just fine, already filled it up half way.
By the way, I recently bought another Sandisk Ultra 64GB micro-SD card at a local Best Buy store. Even though they are selling the card for $99.99 because it wasn't on sale last week, I used my Note 2 phone to go to B&H Photography website to show the cashier that B&H is selling the same memory card for just over $50. I requested the cashier to do a price match, and the cashier had the manager approve the price match and I got the same price as the B&H Photo website! I was so pleased, I bought 2 memory cards for the price match! This is the second time I've requested Best Buy to do a price match, a previous time was for a Creative brand Bluetooth stereo headphone. Best Buy is only willing to do a price match for "legitimate" retailer websites. The funny thing is that the cashier helping me was this young cute girl who never heard of B&H Photography, and she had to ask her male manager to approve the B&H Photography website price match. I jokingly said to the male manager "you being a guy must know of B&H Photo in New York City", and he replied back, "oh yeah, they're legit!" I told the helpful female cashier that all the really large established photography stores are located in New York. I personally have visited B&H Photo in New York City, and they are huge!
Here's the link to current price at B&H Photography for the Sandisk Ultra 64GB micro-SD currently listed for $56.95
Sandisk ultra 64gb micro sd| B&H Photo Video
Apparently, the price of the memory card changes even within a short time, as I had seen this same memory card go for something like $53.83 at B&H Photo just last week when I had requested the price match.
Anyway, that's your tip for the day, always request Best Buy store to do a price match, and you can use the B&H Photography website on your smartphone for a price match reference!