I just bought a sidecar style holster for a M&P9 2.0 to try out, and it is semi comfortable. It will definitely take some getting used to, and some add on stuffs like gel pad or foam wedge.
It conceals very well, but me being fat makes it look weird, but losing some weight is planned after this gym cycle (End October/Beginning November). There are lumps that look out of place where fat is pushed around the gun and mag. I need a new belt anyway, but its tight because it has to go around the belly as well when sitting (because the gun is pushed out, even when adjusting pants.
With that said, especially after cutting weight, this is a very viable carry option.
As far as a bug, I am looking at a small carry option in the front (sheild, G43, etc) that can be a BUG as needed, but do not typically carry a BUG. Even entertained the thought of a P3AT/LCP for true discreet stuff, but havent pursued that thought very far.