Dan, I see bullet weight as only one factor in assessing the effectiveness of a given load, in 9mm or any other caliber. Bullet construction, velocity, and history on the street factor into it too, along with reproducible results in various test media.
The 115 grain +P/+P+ in the 1300 foot-second range proved itself a very dynamic anti-personnel load on the street, but in some iterations would only make a wound channel 10" or so deep, though very wide. FBI felt this was short on penetration by a couple of inches, and many others agree.
The 147 grain subsonic hollowpoints are deeper penetrators, and IN THE MODERN HIGH TECH BuLLET DESIGNS, expand well.
My personal preference is something around 124 grains, going about 1250 fps, with a well-engineered, modern high-tech bullet. They tend to meet the FBI standards and the two most common, Speer's 124 grain +P Gold Dot and Winchester's 127 grain +P+ Ranger hollow point, have an excellent history on the street as well.