I have worn both in southern OK and i agree the fanatic is warmer than stratus with puffy/insulated mid layer.
Honestly when temps are 65 down to about 40, the stratus with or without a solid mid-layer is the bomb.
When it gets below 35, i will always don the fanatic and the closer it is to 35-40 the less i wear under it, from a base layer all the way up to a base layer two mids or a puffy when it is low double digits (been down to 11 degrees with it for a calm morning hunt).
My legs i typically will wear stratus pants or bibs. As it cools i like the bibs for the extra coverage. I wore the bibs down to that same 11 degree morning with a pair of net bottoms, merino over, and puffy pants (kuiu super down pro) under the stratus bibs and that kept me warm. Feet got cold before my body.
The stratus material quiets pretty much whatever is under it, within reason. I was bowhunting and had to stay reasonably still for two reasons, it was incredibly calm so there was no ambient noise save for animals, and the clothing when that cold does make a slight noise by itself. But i could have easily moved to shoot within 20 yards no problem.