Good Evening, Lars,
I think that T-Max 100 is preferable. It has good reciprocity characteristics, and it has the advantage of extremely fine grain. Since most night photography requires a tripod anyway, any difference in exposure length should be insignificant. I seem to recall a test reported some decades ago in a photo magazine which found that time exposures with T-Max 100 could actually end up being shorter than those with T-Max 400. My best results came with Technidol developer.
Konical