Real life Firewire 800 vs 400
I had been using a Lexar Firewire 400 CF card reader to import photos into my 2011 MacBook Pro. Recently, I picked up a Sandisk Extreme Firewire 800 reader and decided to test performance.
Test Parameters: 126 Nikon D300 Raw Photos on Sandisk Extreme III 30Mb/sec CF imported into LR4 running on 2011 MacBook Pro.
Test Results (min:sec): Lexar FW400 - 3:12, Sandisk FW800 - 2:02
I don't know if this 3/2 ratio would hold with a faster CF card.