I agree with Ken.
I've had both WM and FF bags. I prefer FF because of fit. I'm a skinny dude but the 59/51/38 shoulder/hip/foot of WM only fits nice if you neglect layering. I've found that the medium size from FF fits me just right. Wide enough that I can fit a midsized down insulation piece in with me to push its rating while still being snug enough to avoid drafts without layering. It is 60/56/38. The extra inch around the shoulder is great for layering and the 5 inches around the waist make the bags feel big and comfortable.
After all, it is just a bag of down. If you shell out the cash, all the primo manufacturers have got the basics locked in. (dwr, breathable, light shell with continuous baffle designs, roughly the same weight specs, and high quality down) The only remaining question is which one fits you best for versatility and efficiency. Ha. That is a point that favors WM. You can actually try their bags out in person. Feathered Friends seems to have decided that they want to serve the Seattle area only and aren't producing for retailers outside of the PNW.