I've never had Orpingtons, but I've had Australorps, which are somewhat similar. They're beautiful, big and have good temperaments. Good layers. I've also had BRs, and I'll never have them again. They were my meanest chickens (I had to re-home one), and their bluster doesn't match their laying ability. Definitely the weakest layers I ever had.
RIRs on the other hand - weather hearty, phenomenal layers, good temperament. I have nothing but RIRs now.
Keep investigating. If I ever do get another breed, it will be Buff Orpingtons based on what I've read and heard. I'm so happy with my RIRs though, I don't really have a reason to experiment with anything else.