Size doesn't matter. As an example, Synthogy's Ivory II sampled piano takes a minimum of 22Gb and ideally 77Gb of HD space. Then you have 3 extremely good-sounding grand pianos. Does it make it 5 times better than your 16Gb collection?
I've no idea how "big" my collection is nor do I care - it works for me, it has the sounds I tend to need the most. That's enough.