The Nifty Mini Drive is mostly great. You should buy one if you need additional storage for your MacBook. I ordered a Mini Drive after cutting too much into the hard drive space on my main machine, a 2014 15-inch retina MacBook Pro with a 256Gb SSD, which is of course a proprietary part. I love my rMBP, maybe because it was a gift from my uncle, maybe because it’s an all around champ. However, 256Gb of space just isn’t enough, and left me living like an animal with external hard drives and ugly thumb drives all breaking with every move.