I flew NW a lot in the past. Acculumated about 150000 flight miles over several years. I was satisfied as I didn't have any expectations. I liked the fact that certain coach fares upgraded automatically to First if space was available. I typically flew these fares as I never seemed to fly enough to get status, don't know why and I was a newbie flyer at the time.

2 jobs later I found myself by chance on a UAL flight. The major difference I noticed was the inflight entertainment. I then projected ahead to the future. If I was traveling with my daughter to Hawaii (a goal I had), which plane would she rather be on. I also learned that UAL provided kids meals. When I saw the personal screens on the 777 I was sold.

The last two years I have about 80000 miles on UAL. This year I'll end up somewhere between 25-30000. UAL has captured my business.

Last year I did my own comparison between UAL and NW. NW makes a strong play with its unlimited elite upgrades. I live in NW dominated territory as I am about 90 miles from DTW. It seems the mileage bonus at entry level elite is 50% vs 25% for UAL. NW also used 'real' jets at my local airprt, LAN. I decided to give NW another shot.

Alas the first flight I took on NWA was delayed. I got to sit in coach and compare the offerings. Though I could get comped status and use elite privileges for myself, when I traveled with my family on awards to Hawaii I would be coach.

My opinion is that UAL provides a better flight product than NW. First class on NW domestically is simply a bigger seat with more leg room than coach. This is not much better than E+ with an empty middle seat. In fact I could say that I prefer E+ with an empty middle over First, if in First the seat next to mine is occupied.

I have used United to fly to Hawaii on award for myself, my wife, and my daughter. I am going a second time this december. I made the reservations in February for travel in the Christmas time frame. I have been told this is the worst time to get an award seat to Hawaii, yet on UAL I was successful. I checked the NW award availability at the same time and found absolutely nothing. I have since heard many grumblings about the difficulty of getting NW awards to Hawaii.

How will you use your affiliation with your FF program? Are you mainly concerned with domestic upgrades? Use NW. Do you want the most comfortable planes? Use UA. Do you want to be able to use an award? In my experience use UAL. Your destiations/dates will certainl vary from mine. Take a look at http://usr.v7.com/wpaa/ to see if NW is available to where you want to go.

I haven't flown AA enough to give an adequate comparison. I flew Delta to Hawaii on an award and thought their planes were vary old. I did like that they only required 30000 miles for Hawaii Awards. For 3 seats that is a savings of 15000 miles. They have modified their awards effective next year that removes this advantage. Delta also has a more limited schedule to the West Coast than UAL. In reviewing their FF program, they offer nothing significantly better than UA. Their frequent fliers also seem to be up in arms over the changes to the FF program this year.

This is how I would rank the 3 programs: UAL, Delta, NW.