No I've never seen a Martens but sounds like it is a good place!!
I understand that the irregular pellets cut a rougher wound causing more trauma reducing cripples when the shot connects-----but try shooting paper with them at different yardages. The pattern master shot cup does not open at all---find it after you shoot and it will be 15-20- yards out, unopened, which means the pattern did not start to open until it is somewhere in that range. Check the paper there and it should look like you shot a slug, mine did. The pellets being irregular in shape means it is not aerodynamic and become "flyers" leaving an uneven downstream pattern---less pellets coming in contact with the bird. Even though the Black Cloud cuts a more traumatic wound cavity there are fewer pellets doing the work---check your paper at 40-45-50 yards and see it it is getting dramatically more open at those ranges. I competed in Sporting Clays for a few years and spent money on the interior of my gun barrel to prevent flat spots in the shot so I could deliver more pellets down range to the target causing more---Black Cloud proved this on paper to me---just hate to see folks get caught up in a marketing ploy. Remember Phil Roberson gets paid to advertise them!!!!
The regular steel Federal shot works well for me, I shoot it exclusively.