All things equal 243 will still outrun the 6 creed when both are being pushed. Especially with heavier bullets. Only real advantage I see is OAL and mag restraints. Gotta resize and trim anyway. Brass is readily available for a 243 and lapua makes brass for it too. Creedmore is hornady's fancy abbreviation for "-250". I have not owned a 6 creed, but have been looking at it pretty hard over the past year. Decided to stay wih my 243 vanilla and 6br lapua as no major benefit over what I already have. Just my opinion. I guess for a competition shooter the benefit could add up, but it doesn't reinvent the wheel