Hi, i'm deciding whether upgrading the Fusion Drive to SSD is a wise choice for the new iMac. I know that upgrading to SSD is a no brainer but hear me on this. If i upgrade the SSD through Apple, i can get the 256GB.... Or, i can get a 512GB SSD for roughly the same amount of money if i upgrade myself. So what is your choice? To upgrade SSD through Apple... Or not?