I was actually surprisingly impressed with the neatness of the bg on a newborn and just use them with the folded insert which is fine.
I have tried bamboo beehinds but only as a night nappy as I find them a bit bulky especially with the frilly legs which I am not a huge fan of.
I posted about he nb swaddlebees in here a few weeks ago - Ben has already outgrown his! He was 7lbs 15oz at birth and somewhere between 10 & 11lbs now I should think and they only lasted about 3 weeks - I think he has chubby thighs though
So don't worry about them making your other nappies look big, they really are exceptionally tiny.