I'm sure we've all considered that. Thing is, I wouldn't want a big, expensive drive running constantly while I'm sharing files all night. (I can tune-out the sound, but it drives my gf nuts). That's why I wanted to use a solid-state device for LW.

I will likely get a BluRay (1/2 TB disks), and a solid-state drive for my OS and programs (my SATA internals total 3/4 TB). The solid-state drives can experience bit decay, and the devices themselves will eventually wear out with multiple overwrites; so they aren't perfect, but they'll extend laptop use.