I have used it before. My kids love how warm it is. I'm not a pre-washer and I've made them with and without batting. I live in WI and it gets cold here. I used batting with the minkee. If you are in a warmer state, I would probably skip the batting and maybe put a layer or flannel if you needed something in there.
On a longarm, it does work wonderfully. I've sewn it on a domestic machine and it's hard to keep it from sliding around. Your longarmer should not have a problem with it but do talk to them first. Everyone is different and they might have special instructions.

I love minkee. I stitch in the ditch. I pinned like crazy and i used batting. They are toasty and ready for my grandsons. I will post pictures of the I spy quilts backed in minkee as soon as I finish the binding and wash them. Minkee has one way that is really stretch and the other way does not stretch. Just plan for it. I had just enough minkee for the quilt so I made sure the stretchy direction was the direction I was a bit shy on extra. It worked.