So, I snagged the Pacific Trail Heater Fleece Lined Flannel Shirt and I'm thinking that we should rename this as a jacket as I was surprised when I found that it was insulated. I was slightly turned off at first as this gave me a bit of jacket overlap within the quiver, but as I started using the Heater Fleece Jacket, I warmed up (see what I did there?) to it's comfort and charm.
The fleece lining accompanied with the flannel outer actually lends a ton of heat and comfort. There is also a bit of a nylon inner lining that adds to the comfort. I'm glad they used a button down as it gives a more casual feel, but the buttons feel a bit looser than they should so be careful with how hard you pull.
The inner fit is pretty good. 'm 5'11" 180 lbs with a med-smallish torso, short arms, wide shoulders and med-smallish waist and the large works well. The outer fit is a little larger and bulky though as the flannel combined with the fleece inner makes for a bulky upper piece indeed.
I would recommend the Heater Flannel Jacket to anyone who loves flannel and needs a bit of that warmth, just make sure to size down when needed.