the best results i've experienced is using the higher pin settings as a layer in itself.
1) i usually ramp up with pins as close to my chest as possible (luckily i can get <1/2 an inch for inc and dec).
2) then i do my 90% work i.e 8-10 sets of 3.
3) then i set the pins a notch up (2.5-3 inches) and i shoot for 3-4 sets of max reps whilst still using 90% of ramp - i usually hit 7-12 reps per set depending on whether i'm ramping to 1,2,3 or 5rm.
i found it to be a great way to get in some mechanical volume, whilst still using the most weight possible from your ramp. my chest was visually bigger/fuller after about 3-4 pressing sessions this way!
-the most impressive change was actually in my triceps. i guess they play a bigger role when the ROM is shortened.