I have been trying to put all of my miles towards CO, so I have been trying to fly NW and AS as well as CO. I have also been flying alot to Charleston, WV on US and have received great service both in FC and coach.
The few times that I have flown on NW have been in FC and it comes nowhere near the service or food on CO or US.
And I agree with you on the PIT and DTW airports. PIT is really a nice airport. DTW is terrible except for the Mesaba terminal.