I was thinking of buying a ticket from MKE-DFW because its a lot cheaper then ORD. I can rent a car and drive to MKE, but I also realized that I can take the train and it stops at MKE airport. Only 80 minutes from Chicago. It takes me 40 minutes just to get to ORD by subway.

The flight would be at 7:50 and the train arrives MKE at 6:28. This is prefect is the train is on time. In Europe or Japan I would have no issue with this. Is Amtrak very reliable or am I asking to miss my flight?