I am redeeming CO OP miles for reward travel. Possible itineraries are SCE-DTW-ATL-STL or SCE-DTW-CVG-STL.

CVG is definitely the more direct routing, and neither RJ segment is a "long poke." I'm willing to sacrifice convenience if it improves odds of making my connection. Ominously, the DTW-CVG segment shows as operated by Comair. Isn't that marginally better than ASA?

My only alternative flight is NW DTW-STL. Has anyone tried to SDC from DL to NW flight on reward travel?