I am thinking of getting the 15 rMBP in the refurb store with the 256GB SSD. The only way I could get such a small hard drive is if I use the SDXC card slot and store files on it (my 50GB iPhoto library and my 50GB music collection)... I have read that the SDXC card frequently disconnects/unmounts with no warning, ergo, it's not reliable. Is this true? If so, I'm going to have to spend more and get the 512GB model... Thanks!