Pinnacle Holdings existed on paper before the Colgan purchase, it just wasn't being used. The ORIGINAL plan was to start up a non-union carrier. However, the lock was put on that during contract negotiations, so they went out and BOUGHT one. I never could understand how they said they couldn't start a non-union carrier, but they could buy an existing one and keep it separate under a corporate umbrella.
As for the original question....go with the one that's going to give you the better QoL. ATL isn't going to be impossible to get. You'd probably have better luck getting ATL than MSP or MEM in the near future....