OK, I think I've made up my mind. Going for it and ordering the Charge HR. My poor credit card, haha. I liked the sounds of the Garmin Vivosmart 2, which beeps every hour you're inactive, and forces you to get up and move to clear out the "motivation bar"... But there were so many reviews of it being a PITA to sync that it seemed counter-productive.
DH got the daybed taken apart and put in the attic today, so the rowing machine he got from his work is set up now. I'm kind of excited to use it this week! No excuses now - the treadmill, weight bench, and rowing machine are fully set up and accessible, so there is absolutely no reason to not get up and actually use them.