Use both.
You're feeling the pecs more with the DB's because of the more natural arc you're able to use...you almost get a bit of a flye exercise at the same time, which really hits the pecs.
I tend to do one barbell press and one dumbell press on my chest days, to make sure i'm hitting it a few different ways, with different stresses, without over-doing it.
You could also just do dumbbells for a few weeks, then barbells a few weeks, etc. Just try to keep the body from adapting to the stresses you put on it, and you'll keep growing/getting stronger.