In all the time I've used W&N or W&W I have never had pilling of the batting. Now I do use W^W on light quilts only but that should not make a difference.
If someone buys the bagged batting, it is important to unroll/unfold it and let it relax for a while. You can also toss it in the cool dryer with a damp towel to help relax the folds.
I bought my first piece of Hobbs 80-20 on Friday. It is a requirement for my quilting class - to try different battings and this one will be used in trapunto. It feels a bit fluffier than W&N but not as fluffy as Polyester.