It honestly depends on how you play. If you really like organizing your den, having more dens is great. If you like maximizing your professions, being able to mine or cook more is great. I don't think more nests is really necessary. Having more room for apparel could be a thing, but since there isn't all that much site apparel yet, I don't think it's something to worry about for someone who isn't likely to buy custom apparel at this point.