This is not the 4th night free benefit. It appears to be very similar to Amex's FHR. Thinking about staying at Halekulani in Waikiki.

Per Citi website, this special offer includes:

Breakfast for two at House Without A Key (daily/buffet) or Orchids (American ala carte/Mon-Sat)
$100 Resort Credit per room, per stay in regular room or Jr Suite (not valid on room rate - no cash value if not redeemed in full)
$200 Resort Credit per room, per stay for pool view suite or higher categories (not valid on room rate - no cash value if not redeemed in full)
Upgraded room at time of check-in when available
Early check-in when available
Late check-out when available

Wonder if I can double dip this offer with the fourth night free.