Trading in a 2012 Sportsman 500.. 450 HO or 570?

Hey all, I am looking to trade in my 2012 Sportsman 500 but cannot decide between 450 HO or 570.. I basically trail ride and already have a 570 and RZR 900 so this is just a spare so to speak when I go out with others. Is the extra $700 worth it? I see my 500 is actually a few HP more than the 450 but likely cannot tell.. unlike with the 570 of course. Any other major differentiations I should take into account? Thanks!