Good question Shane. . . I was just getting closer to 400 and I was still occasionally (based on release, etc) weak. Just seemed crazy going with that much wt on an arrow to get it to work. I would be far over 700 gr with a boulder tied to the front. Work? Sure. Benefit?? Worth the wt?? Not so sure.
I suppose if I were hunting big bears or hogs at 15 yds and closer the heavy wt. and EFOC makes sense to me. For my hunting of primarily deer species' keeping at 500-600 gr with that 18-25% FOC seems beneficial including that 20-35 yd shot if I feel up to it. I guess I see no big advantage of shooting a deer with a .375 HH, when a .280 takes them down fine while giving some trajectory advantages.
Just my thoughts. . .
Dan in KS