This is interesting - just noticed in the fine print under HHonors terms and conditions on the website:

At Hilton Garden Inn hotels, Gold VIP members will receive the best available room, complimentary continental breakfast throughout the stay for all occupants of the Member's room and a $5 coupon for use during current stay for purchases within the Pavilion Pantry® (excluding alcohol due to local laws).

This seems to be more than per most of the above reports (e.g. usually breakfast, but less often a $5 coupon), and more than my recent HGI experiences. Not sure what the "best available room" is going for many of the hotels w/o many suites or other specialty rooms - but breakfast + a $5 coupon isn't bad.