I let them grow long , I like them this way , quite a lot , especially because my hands are huge and manly , so the nails are maybe the only feminine features .
They don't really stay in my way , sometimes one of them may break because of some housewife activities that fill my time , but it is ok , they grow back quickly .
How long ? I don't know , I would say ' normally long ' for a woman , if that says everything . I don't have an obsession to get them as long as I can , just to look pretty and feminine . Maybe 1/4 of an inch over the fingertip .

P.S.
Sometimes I tend to cut the ring finger nail a bit shorter to give the impression of female digit ratio

( yes , I am obsessed and weird )