I made a switch more toward strength than "aesthetics" over the years. I have built relatively large pecs (or tits whatever as I'm about 18% BF) and I have also managed to build up to a 370 PL style bench.
I'm NOT boasting here, but it is just to give YOU a frame of reference (well, I am proud of a 370 raw bench). In comparison, for PECS, I usually did dumbell bench presses with a very very slight decline angle and got up to a pair of 100s for 12 smooth reps.
The first thing for me in the PL bench is that it really isn't a major PEC exercise. The elbows need to kept as close to the body as possible and I mean that even with my index finger on the power rings, my elbows are practically brushing my lats at the bottom.
In fact, my triceps are compressed against the lat and by flexing the lats, the compression on the tri's actually starts the weight moving.
Also, the PL bench really involves "tilting" the scapula back to get the whole shoulder girdle rotated under the bar. Its more like a forklift. The bar touches a point about 2-3 inches above superior (closer to the head) than the belly button as opposed to somewhere around the nipple area.
You can do this with a little arch, or a lot af arch, and eventually will need to practice flexing everything along the posterior chain from the calves, hams, and glutes and keeping them flexed hard throughout the lift.
Tate's 12 steps was my basis for this about 4 years ago when I started making the transition, but I did not fully understand it at the time.