I have never really wanted a massive chest. Even in my bodybuilding phase (it ended about four years ago), I wanted everything to grow, up to a point, except my pecs. But I still did a fair amount of chest work, and I did put on some muscle. What I found was that while the magazines all preached the bench press as the best chest builder–I agree with this, because it allows the most volume and the most weight–I was able to accomplish as much as I wanted in terms of size with dumbbell bench pressing. And it felt better as well. I also got a lot of mileage out of the dumbbell floor press.
The only reason this differs from the bodybuilding magazines is that a flat press with dumbbells is usually something to bolster the barbell press, but it’s an effective exercise in its own right. It has had value for me both as a muscle builder and a strength builder.
But I do suspect that it never would have led to me to massive pectoral muscles, even if that is what I had wanted. The point came where I was pressing two 110 pounds dumbbells easily, and my gym didn’t have any heavier ones. And I wasn’t interested in paying for my own.
I guess this is all my long-winded way of saying that if you’re interested in more chest muscles, but the barbell bench press is uncomfortable for you, this could be a worthwhile variation to experiment with. I like the fact that my arms can each pursue their own path during the press, and my joints have thanked me.