Different schools of thought I suppose. I preferred carrying water in either my camelbak bladder or in a vendor bottle. It was way more convenient than the Nalgenes for carrying purposes, and with the setup I have and the way I treat the water, the camelbak made better sense. Having a nesting capability for your kit looks like a desirable trait. Being able to mount that filter onto the bottle also seems pretty nice.

I guess it's just different strokes.