We flew with Northwest from Amsterdam to Seattle. It was the first time we have used them, on a friends recommendation. The outbound flight was fine. Airbus 330, flight was not full and had plenty of room for manoeuvre. The entertainment screen in back of seat was a bonus and a good selection kept us all entertained.
Flight attendants were very professional, seemed more mature than on other airlines that I have flown on. Nothing was too much trouble. The food wasn't great but it is only airline food after all!
The return flight was delayed at Seattle for an hour and a half, due to a smoke alarm fault in the hold. This caused me to miss my connecting flight home from Amsterdam to Manchester, but their partner KLM sorted out a seat on the next flight and gave us plenty meal vouchers to compensate for the delay. Very impressed, both with the service, and the way they handled the delay.