Haven't yet received "the cherished plastic," but when I do, I'll be carrying my H&K USP Compact/9mm in condition-one (i.e., "cocked and locked") with one in the chamber and a total of two 13-round mags (one loaded in the piece, and the other tucked in a belt pouch).
For what its worth, the carry ammo that I've tested and decided to go with is Winchester Ranger-T127 gr. +P+.