To be honest I don't pay much attention to ours unless they are being assholes. The way our system (county 911) works is you have a few people that are calltakers who answer the phones and send the call info to the dispatcher of the respective district. They then read whatever the call says on the screen so there isn't much you can tell. The info is usually bare bones and it takes and act of Congress to get more.
I think how good of a cop someone is depends more on them, then what they did prior. That said a dispatcher would have some type of edge over an average Joe just out of the academy.
I befriended a few dispatchers on Facebook but I don't know any of them well enough to determine how they would be as a cop, and here being a dispatcher is a better job than being a part time cop (better pay, county bennies, holiday pay etc.), which is what I am and the way most guys start out here.
"Knowing what you stand for limits what you fall for"
"Hey, I don't know everything just because I'm a CJ student...I know everything because I'm a female." -PathosLogos