Received my J58-WS today. Some quick thoughts:
As already said really warm, leightweight, nevertheless solid feel and a really deep front pocket. Front zipper is rather huge, wasn't aware of that, but not a real problem.
Regarding fit and sizing I would say it is in fact a very profile fit, I am usually between small and medium, went with medium and it fits perfectly.
As my hardshells aren't compatible to the neck zipper, it is nevertheless possible to use the fasthood velcro to keep the liner in place. It would be even possible to use the gravity pocket buttons to button up the liner sleeves, but I don't think this is intended use.