Jon,
What I tell folks that ask about a new rifle is to disregard the hype, guys in marketing get paid a lot of money to create a need in your mind. Go to the accuracy sites, the custom builders, who gurantee sub MOA or in the case of the 223, sub .5 MOA groups. Look at the base gun, Mfg and model, they build on, then buy that gun in a configuration you want.
I own two 223 guns right now, one is a 1-10 and the other is a 1-8 twist. The reason I do not own a 1-7 anymore is because I have considereable experiance with the 1-7 in my 22-250 AI and had I to build that gun again, I would put a 1-8 barrel in it. The 1-7 and the 1-8 will stabalize an 80gr but the 1-7 will only go down in weight to a 60. The 1-8 will go down to a 55. My suggestion is to select a twist that will support the case capacity in its ability to launch a bullet at a desired velocity and for a heavy bullet, do not look to hard at the 80s, look at the 75s for the 223.
If you play the cards right you can have a rifle for every critter, a yote getter, a turtle getter, a deer rifle, a hog rifle, etc.
Best,
Ed