Sorry to hear of your bad experience, but as others point out, only some issues can be attributed to the airline. NW started flying trans-Atlantic with 757s a few years ago -- something I have done on CO and it was no picnic either. The only redeeming feature of NW's 757s is that coach passengers have a few more inches of legroom than most other American carriers.

Trans-oceanic flights in coach are, for me, more of a matter of endurance than anything else, regardless of airline. Flying with children makes things even more of a challenge. Hopefully your next experience is on a widebody aircraft and meets your expectations, but these days, I suggest you lower your expectations.