I have a lot of confidence in RST ammunition and will use them extensively.
I also like the Remington 16ga. ammo and have planned on using them in the second barrel. They are not the hottest or biggest load out there but certainly complement the RST's with slightly more shot (1-1/8 vs. 1oz) and a little additional velocity.
At some point, this becomes a hair-splitting activity. It really is about shot placement with the proper amount pattern density.
I don't have any B&P 16ga. ammo but do think highly of them and have a flat of 28ga. shells in inventory and some 12ga. Int'l Trap shells that are great target loads.