Since they are the same format, a majority of the songs will be the same. Additionally, Mix plays some newer stuff and moves it faster. That's because of their unique competitive situation, WPLJ programs based on theirs. Both stations are middle-of-the-pack 6+ and both do well within their demo. That's life as a Hot AC. You seem to feel WPLJ isn't what you want it to be. But considering you're not a suburban New Jersey 30-something woman, maybe that's why.
As for WODS becoming AMP. That was a move based on the makeup of the Boston radio landscape and how that piece of the puzzle worked into CBS's business plan, it wasn't just pulled to clone the brand. You're blurring the lines between originality and strategy right there.
Thanks for your insight on this, that makes sense!