Have yet to run into any Comp, just don't see it around here often.
My search for Comp is somewhat responsible for this thread.
Without a doubt AR Comp. I use it in .223 and my AR10 308w... But for 69-77gr pills, you are likely not going to find anything better... RL15 works well too, but doesn't meter as well and is not nearly as accurate... I use it when I have to..