Right now OCRP is full of bugs due to GM13 so its hardly ever used. Once OCRP2 comes out though, we hope it will flourosh once again. Its truely is a fantastic gamemode and will be even more fantastic with all the new stuff in version 2. Keep one thing in mind though. The server will be semi-serious so rules and regulations will be more strict then hl2rp, but not as strict.
HL2RP is a strictly serious roleplay server with certain rules and reulations. Its basically like living in the HL2 universe and being able to do things to the utmost realistic point. You have to rp emotions, pain, injury, and fear. The goal is to develop your character. Its basically like writing a book as you play.
You can do almost anything you want, that fits within realism and canonical reglations. You can choose to be loyal to the union or even join the civil protection team. You can choose to be against the union and try to corrupt it. You can hide from the union because you just want some freedom again. You can choose to stay in the city or leave to the outlands which are currently in the mountains.
The city is more of an oppression metropolic rp where outlands is more of a dangerous survival rp.