I too am looking for a great AMEX alternate. I generally use my AMEX platinum for every purchase imaginable. However, there are a handful of merchants who don't accept the card. Plus, the ways AMEX has been reorganizing and paring back spending limits, I may need a good alternate card soon.

My "perfect" card would be one similar to AMEX:
1. Airline lounge access
2. Upgrades at hotels (though Virtuoso can do this for free with any card).
3. Excellent rewards program that would allow $1 = 1 point = 1 mile transfer to a large variety of airlines, much like Membership Rewards.
4. Low(ish) interest rate

In the absence of #3, I would take a branded airline mile card on one of the MR partner airlines.

It seems that MC World Elite might work, but I can't find any good info on the rewards program. Also, the Saks card does nothing for me, and I am not an Ameriprise or Sotheby's customer. Any other MC World Elite info out there?