i've used bamboo, i think it was fairfield, 2x, and really liked it.
i didn't think it was flimsy or limp. it is a little more money than warm and natural but i get it with a coupon. i use it on my long arm, had no tension issues (maybe i was lucky) and see no reason not to use it again if the price is right the shrinkage is about the same and i don't wash batting..