You definitely need the Dylan/Curt - otherwise you're likely to twist the last cross member and lean down. Silverbullet found this to be true with his ski, and I also found it to be true when using a rear cargo carrier with two rims inside (at least 250 lbs. total).

I wouldn't worry about the offroad entry/exit angle issue, I believe several of the Moab crowd have testified that it can actually save your butt (pun intended) if you slide across something.