Since or lad was 6 months old I dropped from 5 days a week to 4 to look after him. As some have said above, it is hard work, I certainly couldn't do it all week.
I found the kids groups to be not that accepting, not because they didn't like me, but more because all they would talk about was breast feeding, diets, clothes and poo.
Mrs FD works very long hours, some times 100+ per week, so I never get time away from Jnr FD, and although I love him to bits, you do need time away for your sanity.
I think their is predudice in the workplace towards male primary caters ie having to justify reduction in hours more than women, leaving early if son/daughter is ill. Although society is changing the expectation is still that the woman cares for the child.