I'm sure this question has been brought up many times, but I'll open the debate again. I have started to develop some pain in the back side of my shoulder while doing flat bar bench. Bar incline, dumbbell incline or flat dumbbell doesn't bother it. I've always heard dumbbells are better anyway however over the years i have not been able to get away from the flat bar bench. Although I like strength, size is my main concern. It has been very hard for me to break away from measuring success from what the bench says. If you know what i mean.

Looking for experienced guys to chime in on if they think dumbbells are better, worse, or the same for mass as bar bench?

I'm about 270ish have lifted for about 15 years and best lift on bench was 385
for 3.