I was looking at doing the same thing for my new early 2015 Retina MacBook Pro and was considering the following microSD card on Amazon UK. SanDisk is a good reputable brand which I have used before.
http://www.amazon.co.uk/SanDisk-mic...N-128G-G4A/dp/B00M562LF4/ref=pd_bxgy_ce_img_y
I opted for a 128Gb sandisk class 10 card. I plan to put my photo library on it, are these cards reliable enough for this usage long term?
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