Useful info - thanks!

One clarification, though: I just about never use miles for award travel, whether domestic or international. I use them for upgrades only (though to be honest, I haven't done much of that lately, either). So I currently have about 275,000 accrued miles on AA that I should probably get cracking applying to upgrades. :-) It occurs to me that I should have put that in my initial description, since if I do a status match to DL or UA/CO, I will get the status, but I won't have any miles to use for upgrades.

Also, AMS and TXL will likely become more common international destinations for me - at least once or twice a year each. AA doesn't fly direct to either city, whereas both UA/CO and DL appear to. So I must weigh that convenience against the benefits of having 275,000 current miles and 465,000 lifetime miles on AA.