I just bought one of the Hevi-13 chokes for my 835. The man to ask how that choke shoots is Clark. He sells those chokes. I know he won't sell a choke that does'nt give great results shooting Hevi-13 loads.
Now I have shot the Indian Creek BDS .675 choke. It shot around 300 in the 10" at 40yds using Hevi-13 3.5" 2.25oz #7 loads. I can tell you this much, out of all the chokes that I have shot so far from Indian Creek BDS .675, Pure Gold .670, TruGlo SSX .670, Jelly head .690, MAD Max .680, Lohman Long Shot .680 Carlson's .675, and several Hasting chokes that none of these chokes would touch the original Star Dot .676 choke I have when shooting the load I mentioned above. Now some may give about the same for total number of shot inside a 20" circle at 40yds, but the Star Dot typically will shoot a lot denser 10" numbers and those are your killer bees that do most of the work in a pattern.