My top has a few puffed hex's, but not many. I don't think it is due to my sewing skills LOL but because I starched my fabric stiff, and it was stored on my design wall (and still is :roll:) I agree with omak, folding/handling will continually cause stretchomg of those edges.
I think if you use a little loftier batting, or maybe two layers under the "poofy" places, it will help to fill out those areas less noticeably.
I love your cheetah quilt!!! And the sampler is gorgeous, it still has the underwater look to it and I think it would make a stunning quilt!!! :D:D:D