My experience and 2¢ worth of what to do is: A) if the rate between Agoda and Hilton is say less than $15 and all the same conditions "appear" to be met, book it on Hilton then immediately make a claim on the hilton price match guarantee. Recent example for Brisbane Hilton, I found a cheaper rate that I think was $2 less, did the booking, claimed, received the $50 as a credit off the price matched room night rate. B) if it is more then this (threshold rate up to you) then find the best rate on the hotel aggregator website, call HH directly make them confirm and price match over the phone and complete the booking. You obviously miss out on the $50, but then don't run the lottery of the rate changing/disappearing and HH trying to find the excuses to get out of the commitment. I also did this recently for Brisbane. Saved $60 on the rate, but at least 100% guaranteed rather then run the gauntlet of the "potential $50 win. C) Obviously if both comparable rates are cancellable, you can't lose. Book and make a claim to get the $50 off plus the saving.