Definitely the D-1. Easiest to wear, very comfortable. Practical zippered pockets. Can move in it, not as heavy as the B-3. My ELC B-3 is heavy and I get too hot in it. Has to be at least below 20 degrees to wear it, but then you can go out with just a t-shirt on under it. The B-3 wears you out. Its still breaking in but I wonder how many years it will take. Arms and torso are constricting. Big fluffy collar, silly front single pocket, but it does look good on me. I appreciate the history and the craftsmanship is great, its just harder to live with. B-6 a good compromise but I sold mine. I have JCs prototype D-1 and a well worn RMNZ D-1 that I picked up from a fellow forum member. The RMNZ is like an old slipper. A bit beat, but comfy and it looks the part of a combat worn piece of gear. Don't have to be careful about where I wear it as it is so well worn. The GW is much more tailored and looks great. It looks newer and sharper that the RMNZ, so it works better when I want a warm jacket and I'm dressed a bit nicer. Just wish the fleece was a bit more golden in tone. I do love them both though! I keep thinking its silly to have 3 top level fleece jackets, but hey, you only live once!
Lately, I have been layering the D-1 over my A-2 in really cold weather. Also just acquired an ELC B-10 and this works great over the A-2, too. Plenty of room, no constriction with the A-2 underneath and plenty warm with the layering! Love the pockets and the mouton collar. Gusseted armpits work well over the A-2 and help the comfortable fit. I never saw the B-10 as particularly desirable, especially compared to my passion for the A-2. I am now a convert!