We have both gold and platinum.. but for the Plat5 promo, its clearly a Platinum promo.. so to ensure that you qualify under the Plat5, charge 5 nights to your Aeroplat or Amex Platinum card, otherwise you may not qualify.

I understand that with the personal Amex gold card, you receive double points for travel. Imo, not worth it to cash in on double points, and Plat5. Ensure Plat5 qualification before moving on to collect the double points.