1) As Mr. Moonlight pointed out, the Visa and MC versions of the Citi AA cards are no longer considered separate products (as of 8/25 I believe).

2) I disagree w/ rgritt. I've applied to about 12 or so cards this year (since February/March), and my credit score has literally gone from a 700 to a 792.

"Cooling off" may or may not be the answer for you. I'm grappling w/ that decision myself right now.

Supplementing w hotel cards is a great idea.

I think what you're asking is a valid question, one that I myself am thinking of: once you hit all the "big cards"--then redeem those bonuses--then what? Churning is getting harder. Trying to find a synthesis on maintaining a balance while traveling multiple times a year is an issue, for me at least.