I agree rdust, 500 top seems pretty high to maintain throughout the burn.
Diesel head, you got similarities with me, king, new construction. Your burning hardwood me soft. I just got home, I loaded 20 hours ago my top is 350 my cat 650. Stove room is 77, upstairs is 72 in center of house, far extremities probably 69. It's 29 outside. Total 2850 to heat. I had the blowers on all the way low, stat at bottom of normal 1.5.
It is peculiar that your not getting more similar results. 26 and 2800 is a lot for a stove to heat. You say open floor plan, do you have massive vaulted ceilings and lots of windows? I have some vaults upstairs but it's only 10'6" guessing. I could see if you had 15'+ of ceiling in big rooms that your heating needs would be greatly increased.
I don't know what the construction standards, differences and similarities are between our towns. I do know my home is five star energy rated, whatever that means. I also spent a bit of money on insulated cellular shades on every window in my home minus bedrooms. These make a huge difference in draft from windows. I get terrible wind routinely, it's blowing right now.