At about 75 degrees, my Princisia vanwaerebecki consistently produce as well as my G. portentosa. Elliptorhina javanica are right up there too. G. oblongonota aren't too shabby, but for whatever reason the G. grandidieri seem to need more heat than I give them. I think one of the reasons a lot of people think the G. portentosa do especially well is that they are cheaply acquired and most people tend to have a larger founder colony of them (which naturally produces more nymphs in that exponential sort of way).