HGI's are a step up from Hampton, so it depends on how much. For the corporate guys its free, for me out of pocket it depends as Garden Inns they are you a made to order breakfast or the points? Some properties offer both and those I keep in my top drawer as the properties to say at. The cheap ones that make you choose well, I try not to do repeat business and generally a little messier than when one is good to me. The Hampton by Hilton in Dubai is a great example of a Hampton that is far above expectations like the Hampton by Cancun airport. The Hampton by the Airport in Instanbul or the one on Bridgeport Road in Richmond, BC well they suck.
The standards are the same for all but the owners sure make a big difference, both good & bad.