2) Magazines aren't available in capacities over 15 rounds.
Mine came with a 27-round magazine. They're after market and reliability is iffy but they exist. PCs are interchangeable with Ruger P pistol magazines so if you can get hi-cap for those then you're good to go.
Anyway I own a Ruger PC9 with ghost ring sights and it's very accurate for it's class.
Pro: It's built like a tank. Very robust and reliable.
Con: It's heavy for it's size.
Pro: Aftermarket hi-cap mags are inexpensive and readily available.
Con: Likewise they have reliability issues. My 27-rounder works perfectly though.
Pro: Disassembly is easy.
Con: Reassembly is difficult and tricky.
Pro: Barely any recoil at all.
Con: Did I say it's heavy?
Pro: It's accurate for it's class.
Con: Trigger is heavy.
Pro: If you have Ruger P pistols then you can use the same mags for both.
Con: It is (by it's design) uncustomizable as far as the stock goes.
But keep in mind that these were designed for police duty. PC stands for Police Carbine. So I guess they focused on robustness and practicality more so than sporting aspect.
In the end it's my favorite gun to shoot and one of my favorites overall. I certainly don't regret buying it.