NW's times seem reasonable for O&D travelers, especially for travelers in West Michigan who may not want to wake up at 4 a.m. to make a 6:30 a.m. departure. Also, for NW travellers, it will probably cut a couple hours off travel time each way vs. a connection in DTW (land, taxi, deplane, tram/walkway/tunnel to connecting gate, wait, board, taxi, takeoff), plus eliminates the possibility of misconnecting and greatly reduces the likelihood of lost/delayed luggage on that business trip to NYC.

AA GRR-LGA 6:30a-8:29a ERJ
CO GRR-EWR 6:35a-8:28a ERJ
NW GRR-LGA 8a-10a CRJ
CO GRR-EWR 5:35p-7:50p ERJ

CO EWR-GRR 6:45a-9:06a ERJ
CO EWR-GRR 2:40p-4:45p ERJ
NW LGA-GRR 5:35p-7:42p CRJ
AA LGA-GRR 6:40p-8:55p ERJ