Old argument... recycling, there seem to be two main groups of readers, one lot have an eReader and carry a handful of books being happy to make a choice in advance of whatever they may fancy reading... the other group have an eReader that they want to be an eLibrary so that they can choose what to read when they want to read rather than in advance... the two groups seem incapable of understanding the other's viewpoint
The eReader faction could probably get away with half a gig or much less, the eLibrary faction rather like 16GB plus