Amex Fine hotels and Resorts.
While that also books through Agoda, it's normally recognised as being similar to Impressario etc.
Amex stays otherwise don't book through a GDS so you won't get points or status benefits, and aren't meant to under the T+Cs.
I suspect it's possible to get a human at amex travel to book your hilton stays through their GDS, but not sure if you can then use the credits with that. Plus you have to talk to a human there, so why bother.
While that also books through Agoda, it's normally recognised as being similar to Impressario etc.
Amex stays otherwise don't book through a GDS so you won't get points or status benefits, and aren't meant to under the T+Cs.
I suspect it's possible to get a human at amex travel to book your hilton stays through their GDS, but not sure if you can then use the credits with that. Plus you have to talk to a human there, so why bother.