Meh... buffs are average to me. Definitely NOT the friendliest of all my birds.
Beware of true Araucana. Most sellers I have seen don't have Aruacana at all or call them "American Araucana"! They must have ear tufts and be rumpless IMO to be the real deal.
To me Orps are average layers for a dual purpose bird, and they are heavier bodied so eat more the produce less eggs than some other breeds.
Some chicken comparison charts...
https://livestockconservancy.org/images/uploads/docs/pickachicken.pdf
http://www.sagehenfarmlodi.com/chooks/chooks.html
Think I would choose a Rock over Orpington. And unless true Araucana, I would choose Easter Egger or true Ameraucana. Raised 100 + birds of many different breeds... May always have a Rock and and EE, here. Already let go of 1 buff Orp and 2 Lavs.. guess I'm not impressed. But they are perfectly good birds and nothing bad to say about them. And they are all the same to me regardless of color. All will be individuals and I've had a mix of friendly (hanging out close enough) and flighty. But never a lap sitting Orp.
Oh wait... now I see that's what you have not what you are thinking about getting per say.

Is your Araucana correct?
I'm sure they'll be great whatever you choose. I'm thinking Speckled Sussex this year.