I'm thinking of getting the base 13 MBP with the bto 128 SSD upgrade. Then using the OWC Data Doubler with 240GB OWC Mercury Extreme Pro SSD and 5 piece toolkit to replace the optical drive. My question is regarding running 2 different SSDs. One SSD would be the apple bto drive (128) and the other would be Mercury Extreme Pro SSD (240). Any thoughts? PS - this is about the same price as getting the 256GB SSD bto option.