The only thing I've pre washed is flannel, and maybe something from a garage sale if it isn't "fresh" smelling. So far I haven't had any problems. I'm not a starcher. I have Best Press, Niagara, and the old discontinued Bounce. They don't do much for me. That being said, I don't do intricate quilts, mostly patchwork or strips.
Also, to the OP, we have a search function you might try using as a start to your questions and then go from there. I'm pretty sure the wash vs. no wash has been discussed a bunch of times. And still no consensus!!!