Hi,
Over the years (40) Ihave used every kind of batting. In the beginning all that was available was that very puffy polyester. I most recently purchased one of the new batts made from Bamboo. It is very thin and seems to quilt beautifully. It was a little pricey but I purchased a queen size batt and will cut it up to make several wall hangings and at least on bed size quilt probably twin size. JoAnn's carries them and the next time I will use my %40 off coupon. I am a handquilter so I make sure any batt I use is easy to needle.
I have noticed that batts are getting bigger. I think since so many people now long arm larger batts are necessary as well as the fact that newer mattresses seem to be so much deeper. At least we are getting more batting for our money.