I've always used Warm & Natural but I decided to try a few other bats. The last quilt I did I used Legacy bamboo/cotton blend and I pre-washed it. It came out very soft and silky, was very nice to quilt on, no bearding, nice and supple. I liked it better than W&N overall.
I've got a few other bats to try and I'm really looking forward to trying the wool batting that I got on sale!!