I don't know...
All else being equal--which is a critical qualifier--a Dad is still not a Mom. There is real biology in this, and while that makes feminist heads explode as far as the eye can see, I think a Mom does a better job with small children than a Dad in caring for them day-to-day. That does not mean a Dad can't do a good job. The word "better" has an exact meaning.
As kids get older, it gets less important. In recent years, I've been the primary caregiver, but my kids were in middle and high school. When they were in primary school, and we did have to resort to day care sometimes, we found a wonderful Mormon mother who took them into her home (we don't live near relatives).