ZiPS has them projected with a similar OBP for the season, but BJ is a pretty clearly superior offensive player (assuming they get on base at the same clip - which seems reasonable) due to his slugging.
If we are going to give the most plate appearances on the team to one of BJ or Simmons, I think I pick BJ pretty easily - at least for now.
The real question is what to do once they both are OBPing around .300 in mid-May (which seems likely). I guess you just punt the leadoff spot a la Dusty Baker or put Uggla up there.
Heyward and Simmons have been popping everything up - should be something that can be corrected, but it's kind of brutal to watch at the moment.
So pumped at Justin Upton's start. In the far back of my mind I thought there might be a chance some of his power numbers were a bit inflated by Chase Field and he might not have legit power.