I've never tried Picanha on the grill. I normally sear it on both sides, and then bake it in the oven @250 for about 1hr and 10 min. It's pretty delicious and pretty darn close to Prime Rib in taste and tenderness.
I've never thrown it on the b'que grill. (I don't do much grilling these days with heart issues as the smoke bothers me - sigh)

However, I think it would probably taste excellent on the grill.