I have gotten upgrades frequently at Hampton Inns to the "& Suites" portion, which generally isn't terribly useful because most of my stays are like yours. Breakfast is a benefit wasted on me because about 80% of the time I'm out of there before they even set up breakfast in the morning. I will say that generally Hampton Inns and HGIs (I stay in a lot of small towns, or airport hotels) when I mention I won't be around for the breakfast will tell me to grab something from the pantry for no cost. I'll never forget Vicksburg, MS where the Hampton not only upgraded me to a massive room but they had an evening reception... my business was going to have me miss it the couple of nights I was there... I came back from dinner to find a six pack of beer in the mini-fridge with a note from the front desk inviting me to have my own happy hour whenever I was done for the day.

Been awhile since I had a meaningful upgrade at a full flag Hilton other than to something with a better view (like LAX with runway view).