Feminized seeds are produced by stressing a female into making pollen, and that process can carry a tendency toward intersex traits into the offspring. Regular seeds come from a normal male to female cross, so they generally show fewer surprise bananas late in flower. I found a fairly balanced writeup on
https://breederregularseeds.com weighing that stability against the convenience of not culling males. Neither option is perfect, but for a long run of the same cut I trust regulars more.