Now that I'm only getting ~1.3% cash back. This card is a breeze to use. I just call ahead before making purchases.
Last month of the promotion was a pain in the a** for me. Glad I don't have to go through that again. One time, I was on the phone with Fraud Dept. rep and she blurted out something to the effect of 'people are going crazy doing cashback promo'. I just smiled and didn't say a word.
Amex is by far the best card when it comes to making large purchases. I do call ahead time to time, but never had issue... Except for the last day of OBC.