i have about 20gb of data that I need to move from old MBP to new rMBP. Is moving to DB and then transferring folders faster than AirDrop to AirDrop?
Unless you have some screaming fast Internet speeds, I believe Airdrop will be much faster at around 8MBps. Make sure the machines are not on the same wifi network or it will use the router for the transfer and not the direct Airdrop connection. So just turn on the new rMBP wifi but don't join the network.
Why not just turn on File Sharing in the Sharing preferences pane, and then copy the files across the WiFi?
Would that be as fast as AirDrop or DB?
Connect a network cable to each of your mbp's
I guess I'm hopelessly old-fashioned, but to me the "fastest, easiest" way to transfer 20gb of data between two MacBooks would be a USB flashdrive.
If you just have a smaller-sized one (say, 16gb or 8gb), do "multiple passes" as required.
Probably as easy as messing around with anything else!