They keep changing their policies around. You can't use it at Dunkin Donuts is the only exclusion which they did not inform me about at check in but the drugstore is allowed now but wasn't allowed last time. You get $80 in breakfast credit and another $100 property credit, but you have to be careful with the $100 property credit. You can't go back to the regular rooms (Premier King). Once you stay at the signature suite, the regular rooms (Premier King) are a huge disappointment. I stayed at this hotel 6 months ago and booked the cheapest room (Premier King) and got upgraded to the signature suite with a harbor view too. In order to get upgraded to a signature suite, you must book a king bed room with a harbor view (Premier King Harbor View), which is like $50-$70 more per night than the cheapest room (Premier King) so that you can get $500 more value to be upgraded to a signature suite since that is the next 1 level upgrade. It is the same exact room but with a harbor view. To be more specific, if you book the cheapest room (Premier King), you will only be upgraded to the same room (Premier King) but with a harbor view which is not really an upgrade. The hotel changed their policy and now is only offering a 1 level upgrade. The prior reviews from other AMEX FHR customers say that if you book the cheapest room (Premier King), you will get upgraded to a Signature Suite.
