What holster and WHY?
OWB or simple-IWB (P80 and P320)
As far as all-kydex "shell" type holsters are concerned, the most signifant difference between makers is the finish work and fasteners. Vedder does excellent work, and has become my choice for OWB range or competition rigs.
Vedder for V2
Comfort IWB (P320 and 365)
When I carry IWB, it's usually without an undershirt tucked into my pants. My baby soft love handles require a soft backer, which steers me into a "hybrid". Black Arch are the only hybrids I've found that the kydex shell wraps around the back side to cover the trigger. Most hybrids are a sandwich, kydex pushing your gun into a leather back. The only "con" is that Black Arch doesn;t yet support Polymer 80 models, but these are what I use for my p365.
There still isn't a ton of holster support for the single-stack P80, but Knightfall customs does good work while charging poor-end prices. They also offer a lot of clip-options, as well as apendix and light-bearing joints.
Vedder for Compact