Thanks for the post, but as I'm sure someone will come in and correct your maths at any moment, I'll do it first :)

Over serial, 4Gb would take nearly 5 days to transfer. Over USB it's take about 5 hours (currently, though we've got some tweaks to the driver which should halve this, fingers crossed). The point is, you don't do this sort of thing on a daily basis - you have a big splurge at the start to load your collection, then it's just maintenance. You don't do 4Gb a day unless your musical tastes change a lot (and remembering that 4Gb is 70 hours of music, so it'd have to be every 3 days so you could listen to the old stuff first... and you'd not have to sleep either).

Hugo