I see why this thread isn't very active - Hilton just deny practically every BRG, unless you are lucky enough to find a lower rate on hotels.com / expedia (which it seems they've yet to invent an excuse for...)
Yet another BS response from Hilton...
I regret to inform you that we are unable to approve your claim. Easyclicktravel does not confirm the rate and booking immediately; thus, making the website opaque.
The original rate on my booking was fine, so I was just trying out the BRG, but it's hard to avoid a bad taste in the mouth when they invent excuses to avoid approving claims.