for hand quilting i like hobbs wool first, then the 100% cotton- then the 80/20- there isn't a whole lot of difference- really- other than the 100% cotton is not quite as (stable) as the 80/20---will pull apart easier---the 20% polyester in the 80/20 adds that little bit of stability-and loft- i prefer the 80/20 on really large projects for that reason- if it's a smaller project the 100% cotton is nice...both needle beautifully-
i do think the 80/20 has a little bit more loft (due to the polyester addition)
my favorite though is wool.
I do not like warm & natural at all for hand quilting- any batt with a scrim (a net the fibers are punched through) is more difficult to hand stitch. (and i kind of think it's funny- the people who claim to only use cotton & only use warm & natural...since the scrim is not cotton)