How does it prevent cheating? It's primarily interesting for match making, isn't it? Ignoring gimmicks like XP and dropped items.
Prime Matchmaking is a completely separate queue from the regular free to play matchmaking, so because you have to pay for it it's a barrier against cheaters, as when a cheater gets banned if they wanna cheat in Prime Matchmaking again they gotta phony up more money, but Valve will know who made the transaction and see it's a cheater they banned and promptly ban them again.
I checked it out a while ago, but can't say I'm overly hyped after the initial "wow". I'm too old now for competitive gaming, it just takes up too much time. I might play a little once it's a better experience, but can't see myself getting into it again. I will however watch some tournaments again in the near future.
You know Counter Strike Global Offensive added co-op missions, both official and custom made.