Just giving a basic overview of the two scopes. Having owned both, the 30mm tube on the Prostaff, quickly outperformed any lens coating that is "claimed" to be better on the Monarch.G, You are mostly correct. The MONARCH 3 also is a 1 piece tube and the glass coating's are better then the ones on the PROSTAFF 7. I haven't had my hands on a PROSTAFF yet but have heard nothing but good things from those who have. I have a number on MONARCH 3's and 5's which I am very happy with. If you are going to turn knobs I would get the PROSTAFF 7, a lot more internal adjustment with the 30mm tube. If you want to use the BDC reticle with Spot On go for the BDC. Both scopes can be used eith a Nikon Custom Turret too.
http://i1216.photobucket.com/albums/dd363/bman940/MONARCH 3/MONARCH3.png