You are correct, I was swinging on too steep a plane. Now, I am swinging more flat.
Before stack and tilt my drives went 240 yards, but really high (no tree could stop my drives), and I over swung by quite a bit.
Now that I am using a shorter and more controlled swing, I can try different things. Without swinging that fast I am getting 220 yards of carry. This is in line with a 10.5 degree driver at about 95 mph. When I make a faster swing it is farther, about 240 yards of carry. However, I can feel the strain on my injured shoulder. I can probably swing 15% to 20% faster than that, but I would definitely re-injure my shoulder. Not worth it for 30 to 40 yards gain.
In any case, I can control the swing speed with stack and tilt. I can go as fast or slow as I want. 220 carry is just fine. A typical carry plus bounce and roll is about 235 yards.
Right handed, my drives only about the same because it feels so awkward. However, I probably could drive much farther, but need to improve flexibility for the follow through to prevent injury.
I hope I'm not embarrassing the stack and tilt advocates with shorter distances, because I am really happy about my progress.