I know the current nMP design, at least in Apple's standard or BTO configurations, don't come with an awful lot of internal storage - only up to 1TB. And there is not much room for expansion later on should you need more down the road. Apple is pushing for storage to be attached externally as the future. But what kind of data transfer speeds, in practice, that you can realistically expect from the internal PCIe SSD, versus something connected externally via Thunderbolt 2? Assuming that external device is also SSD, not a spinning hard drive, as that would be an, well, apples to oranges comparison. I know there aren't terribly many Thunderbolt 2 SSD external drives at the present moment, but assuming manufacturers will slowly adopt such interfaces down the road, we'll expect to see more. Indeed, Lacie will be releasing their TB2 SSD ext drive very soon. But my concern is, if the internal storage is significantly faster, that will be a huge bummer because unless Apple decides to provide DIY upgrade parts later, you'll be stuck with maximum 1TB of internal "fast" storage but infinite external "slow" storage. If it's the other way around (TB2 external storage is faster) then that's probably ok, because you could keep just your OS and some seldomly used system files there and rely on "fast" external storage for your day to day tasks. In this case even just 256G of internal SSD would probably be plenty, because you would be buying external drives yourself anyway. I know TB2 is supposed to be 20Gb/s, but that means nothing to me. I am looking for some real world figures if any one has any experience. Thanks in advance.