For those who might wonder, I ended up buying both, and the Duet does indeed have somewhat more airflow. It's still restricted, but not as tight as the Venna. Personally I prefer the draw on the Venna, but both are really nice atomizers. I'm going to try some chunkier coils in the Duet, I think it can handle them. Neither have gotten hot on me so far, but I'm not running the beefiest coils, just 2x27/42 and 3x26/38.