Very nice post. The major US airlines generally have degraded the value of FF miles generally and elite status. United seems particularly bad at recognizing its loyal customers.
I tend to fly AA more and am lifetime platinum. In the old days, I would often get unrequested upgrades from business to first on the BOS-LHR flights but haven't received anything like that in several years. About two years ago, I flew coach to London and after I had taken my seat, a flight attendant came to my seat with a new boarding pass and said, "I think you would be more comfortable in seat 12D," and the unrequested upgrade was very nice.
I have experienced a couple of times when elite status was worth the effort. Shortly after September 11th, I noticed that Boston to Tokyo flights were about $500. I immediately booked a two week trip to Japan for my whole family. On the way back, our flight was delayed for hours at Narita while AA sent to Taiwan for a spare part. We sat in the Admiral's club lounge eating sandwiches late into the night. When we arrived in Chicago for our plane change to Boston, we had missed our connecting flight by hours. We went to the transfer desk and went to the first class line instead of the long, long coach line where they said, "Hurry over to Terminal X -- we've got you on the last flight out tonight." We took the bus to the other terminal. The gate attendant looked at me and said, "I've got seats for you and your wife, but your kids don't have seats." Not one to spoil a great vacation by getting angry, I had decided to make an adventure of staying in the airport Hyatt or Hilton. Then the gate attendant looked again at my record and said wait a minute. He spent a little time playing with his keyboard and then called out, "I need volunteers to give up two seats on this flight to Boston. We'll pay for a hotel, provide $200 vouchers for future travel on American and you'll go out on the first flight in the morning." A nice young couple stepped up for this deal (just as my wife and I had done prior to having kids). I'm pretty sure that the gate attendant did this because of my elite status.
And, I've been treated very nicely on award flights on Cathay on which my family and I were flying coach, in part because of the elite status. The nice treatment was on the plane and in letting the whole family into the super lounge in Kai Tak when waiting for flights. My family and I were able to go into the very nice Qantas lounges in Australia -- although my family flew paid business class to/from Australia thanks to a very nice client, we all flew coach all around Australia on a vacation and got into the lounges because of the elite status.
That said, I can't think of anything special happening in the last two years on AA (or any other airline on which I fly). I was able to get award seats over Christmas break this year to Leon, Mexico but think I had to pay the higher rate. I was able to use UA miles to put my son on a Boston to Denver flight so he could do Outward Bound this summer (at the lower rate, I believe).
But, based upon what I've seen in the last two years, I wouldn't invest heavily in getting an elite status, unless it was on a non-US carrier like Cathay. And, especially not on United. One could probably buy tickets and membership in Cathay or Qantas airline clubs with the money you save by flying discount carriers. And, you'll probably feel better about yourself, to boot.
Good luck.