I wear the DSG and JMCK holsters in the highest set of holes, whether with the clip or the PTD loops. That allows the holster to ride lower in the pants for better concealment and prevents roll out for me while still providing a good grip.
There are times when depending on where or how I am seated I'll get some protrusion...but generally I don't notice it much and I try to maneuver the holster a bit before I sit. The PTD loops help a bit in allowing the holster to cant and self-adjust some.
I'm generally not in NPE's much so I don't have too many issues with cover garments.
The major advantage of the G19 sized holster is that the shorter length adds a bit to both comfort and not driving the holster northward (as much) when seated. (I primarily use the 19 holster with the G26, however.)