My colleague Stefan Green (exegetisk teologi) pointed me to Danny Zacharias (Deinde) who announced that a new unicode font for papyrology and textual criticism is available, IFAOGrec Unicode. There are also other versions for transliterations, and Coptic available. For description, samples and download, see here.
Up to this point I have been using Gentium (for Greek) in combination with Cardo (for some special sigla), but sometimes I haven't been entirely pleased. Anyway, this new font seems very nice and should be of good benefit for papyrologists and textcritics.
Comments on your experiences with fonts are welcome!