No, your not missing out.
I used to have this crazy fetish where I only wanted girls with DD or larger--and they had to weigh under 130. I sort of got off on everyone looking at whatever girl I was with with open mouthed stares from both girls and guys. I sort of enjoyed the comments from my friends and their jealous girls about "what is it with you and girls with huge boobs?!" Sex with them is ok, same as any other girl really. Except when they are on top, their boobs make this clapping sound from them hitting her chest. I'm currently seeing one girl who is a DD, and another who is a DDD--but she is 5'8", so they don't look that massive on her.
Anyways, I'm over it-- I would much rather have an athletic girl with perfect thighs and a 6-pack over huge boobs anyday. But don't let that stop you from getting one if you want. Oh, almost forgot, huge tip: If you want to get that girl with huge boobs to go out with you, don't be like every other guy in the world and look at them. Girls with big chests know when you are looking, even if you think they don't. The key to getting one to go out with you is to 1) don't ever look at her boobs, even if she taunts you and sticks them out at you, grabs them etc. Not looking at gigantic breasts on a slim girl is something that is incredibly rare and takes effort. You are already in the door if you can do that. And 2) If she asks you about them (she will) say "I'm not really into big breasts, sorry" We both know that you are, but you can't say it or show it at first.