Firewire/USB and there's the rub. Firewire and USB-2 have similar download speeds, however firewire 800 is about double both of them. The problem is can the card pass the data fast enough? Looking at some transfer speeds on the Lexar stand ay Focus, Firewire 800 doesn't transfer twice as fast, it looks like about 25% faster. And this was with the UDMA cards Lexar have introduces , using the UDMA readers.
If you've a lap top check to see if it has an Express card slot. If it has you may be better off getting an reader that fits in this. Delkin do several I believe.