Just picked up the MacBook Pro Retina Late 2013 model. 2.4GHz, 256GB, 16GB. Using BlackMagicDesign Disk. Read is on par at 700 mb/s but Write is off by 150 mb/s. I think I may have gotten a defect and am thinking about returning. I still want a MacBook but may choose to place a new order because I am worried that Apple may give me a refurbished one if I ask for an exchange. Any opinion? Appreciate it!