Originally Posted by boris10475

There is no magic OTA at least for the US. You go through the usual suspects - the big aggregate sites like kayak, hotelscombined and trivago and check if they link you to better rate than IHG. If not you just move along. Very often times if the majors have nothing you will not be able to find anything on other sites, so you just move on instead of wasting your time and checking dozens more sites.
I have specific Japanese OTA which worked very well for me for bookings in Japan including BRGs on Intercontinentals but I am not aware of any other country/continent specific OTAs for BRG purposes.