I finalised by booking for LondonHouse Chicago around week ago for a stay early next week and booked a non refundable Honors discount rate. While looking at Google Maps to see some things nearby I clicked on the hotel which shows rates from 3rd party providers.
I could have booked the same 3 nights using expedia.co.nz for close to $100 cheaper for a 3 nights than the Hilton site, and that's still the case right now.
Hilton rejected the BGR because (as expected) it was booked more than 24 hours ago, but the whole situation where Hilton can offer properties so much cheaper elsewhere than their own site is quite frankly ridiculous. Just on $30 a night difference is pretty significant - it's not like the difference is only a few $
There shouldn't really be a need for a BRG because Hilton themselves should be offering the best rate possible.