Tremendously helpful opinions from everyone. Thank you!

I have not decided yet, but now know enough to make an informed decision the morning of.

Some other factors I didn't mention which will greatly influence that decision are:

- how comfortable Hyatt Regency's bed is / therefore how close I cut my airport arrival time

- whether or not I owe AA a copay for a cleared J upgrade

- whether or not I am hungover upon arrival

If I try for CL, I will be sure to ask about whether there has been talk of limiting access to regular AMEX holders, and report back.

I can say the official website still lists $50 payment as an option:
http://thecenturionlounge.com/info/access#q-who-is-eligible-to-visit-the-centurion-studio
"All other Card Members with a valid American Express® Credit or Charge Card are eligible to purchase access to the Lounge for $50 per day, subject to space availability."