I keep hearing about d-bells using stabilizers and barbells not. I think there's a benefit w/ d-bells as far as knowing if you have one side stronger than the other, but I would think a barbell bench also uses stabilizer muscles.
Even if it doesn't use the stabilizing muscles as much (I mean, how much more can it be?), I wonder if the extra weight that you're able to do with a barbell makes up for it.
Anyway, I agree that you should use both and don't stick to any one exercise for too long.
Be sure to work the back of your shoulder and your upper back as much as, if not more than your pushing exercises.
I had terrible pain in my right shoulder, benching all the time, but once I started adding more rows AND deadlifts, along with switching up my pressing exercises, I was able to get rid of the shoulder pain completely and now I'm benching a whole lot more weight.
Sorry about the run-on sentances and all the commas.