I've a 160GB drive in my laptop and I could do with more. I have it connected to a keyboard/mouse/monitor when at my desk turning it effectively into a desktop. Granted I don't need more than about 300GB but very few desktops need more than that. Bulk storage is where the size is required and then you are generally less worried about speed. My NAS is 8TB and there's no way I'm using even hybrid drives in that because it's only serving media across the network.