Cozy 22.5 degrees this morning in the bathroom, the heating ran for 5 hours last night. Without it, it would probably have been around 21.2. Worth the few bucks to me :)
I would almost bet that at least you wouldn't notice the 1.3 degrees in the upper floor.
I'm not very keen on manual daytime increase, so I'll test the optimized setting that was used in winter without sun starting in October (for autumn). It was just a pity not to do this from mid-February with so much sun.
Regarding the heating rod, it was completely off this year, and we all know how the temperatures were this year. The heat pump has been working very well and efficiently without complaints since the optimization at the end of January. By the way, the hot water is still only running through the heat pump, the heating rod is off there too.
I had everything installed because when the heating rod is in everywhere, a normal person only notices a defect when the electricity bill's additional payment arrives.