Couldn't find a trader for the HX rims, so I put my winter tires on them.
Carrying the wheels up to my porch, I thought, "wow, maybe it's my imagination, but the Michelins feel lighter?"
Stock rims + (worn) Bridgestone Potenza RE92: 21.93lbs
Stock rims + (worn) Michelin Energy Saver: 21.29lbs
HX rims + Nokian Nordman 4: 26.73lbs
The stock rims weigh very close to the same as HX rims, so the Nordman tires are around 3.75lbs heavier than RE92's and 4.5lbs heavier than Energy Savers.