I have a full size PX4, I have well over 3000 rounds through it, and it is my daily carry gun.
What I like about the firearm:
-The gun is above all reliable, I have only had one FTF with the weapon and it was under adverse conditions and was ultimately the fault of the magazine.
-The gun is accrate, I shoot better with this platform than I do with anything else (save 1911's)
-The gun is comfortable for me me hold/shoot/wear.
What I dont like about the firearm:
-plastic guide rod, this was the first thing I replaced on the pistol
-beretta's night glow sites are rubbish, i replaced them with proper tritium sights.
-the safety/decock is silly and uncomfortable to run the slide aggressively, this was replaced with a low profile slide catch, and decock.
You can see some photos of my changes (and the gun itself) Here.