Cam Man
I second what colobohl said. I also use 2 blade Magnus (125's) and I have had no problems with blood trails. IMO a 2 blade head (of quality construction, and out of a properly tuned bow) will out penetrate any other head out there...no question. I've had some incredible results with the Magnus heads. I'm sure the Zwickey heads are very good as well. Like 5 shot said, they've been killing deer along time with 2 blade heads.