I've played with the idea of getting a 9mm AR, but I've been told they are difficult to keep running. I still want some sort of 9mm carbine though. What are my options? The only other two I can think of is either the CX4 Storm, which seems a bit pricey. And the hi-point, which (dont ask) I refuse to pick up. So what else is out there that I'm not aware of?