Underfloor heating with a brick ceiling?

Hello, I'm joining in here again. Is there anyone who has meanwhile installed [Ziegeldecken], possibly also with [Deckenheizung]? We were offered this again today and I find it very interesting, especially because of the easier installation of the electrical system.

On the other hand, I've already occasionally read that you have to heat more than with underfloor heating to reach the same "perceived" temperature.
Is that true?