With the RAW files of the D800 hitting 40+MB (70+ uncompressed), and the ALL-I video codec hitting 90mbps (44mins in 32GB), on a long trip, the old 1TB drives can run out... not to mention the old USB 2.0 looonngggg download times. Assuming one shoots 600 shots a day on the D800, that's 24+GB x X number of days and having redundancy. My 1TB mini drives get filled up pretty quickly.
With the larger file sizes and longer times, I still don't want to travel like I do for a Red shoot (12TB RAID units etc etc). However USB 3.0 and eSATA are necessary for speedy transfer and backup. I use the CALDIGIT USB 3.0 express 34 card and the AData eSATA Sil3132 card. With newer laptops, USB 3.0 is standard and I think very necessary (damn you Apple!
I just picked up 4 of the WDC passport 2TB USB 3.0 drives. I'll put a 2TB in my laptop (disassembly required!) and use the 4 on USB 3.0 as backups. Unlike the more serious photographers like Alex Mustard, I don't like weeding out the throw outs all afternoon when on location. Usually I don't have the time, but also I can't be bothered.
With USB 3.0 speeds being fast enough to compete with eSATA, it is the new standard in quick port transfer. It is also bus powered unlike eSATA. I'd still use eSATA for video like RAID because it is faster for large file writes but Red SSD readers now USB3.0 and FW800 ready, I think eSATA is going to be out the door sooner than later.
