If you are going to ride the bike park and the option for a DH bike exists whether it is renting it or bringing your own, go with the DH bike. Even if you've never ridden a DH bike and think "oh, I don't know if I need a DH bike, maybe I'm not fast enough for a DH bike, maybe I won't be able to handle a DH bike, maybe it's too much bike for me." Shut up. You don't need that kind of negative talk in your life. Get the DH bike.