Go ahead and drop them. Flat benches are only usefull for beginners who have never lifted and not only will gain from just about any movement but need to work on their coordination as well. Concentrate on the heavy dumbell inclines with full range of motion, the bench and cable flyes, dips (weighted even better). Lately I have been using dips as a last movement in my chest workout combining them with the cybex pullover machine and have really felt a rib cage expansion and squarer look to my chest overall.
