@caranconnor I'd happily let MIL (and FIL) look after any of our children as babies and toddlers.
School-age and up, no fucking way.
They have some views we do not support and I don't want to engage in damage control every time we pick up a child from them. They also do not deal well with teenagers at all and I can already see the constant grandparent-fights, which I would want a child to go through by themselves.
Toddlers and babies though, according to PIL, are at worst a little demanding but mostly cute and can do no wrong. I also cannot see them talk about the things we're concerned about with a small child, so that is a non-issue (and I doubt a pre-schooler cares all that much about their views on history/politics/society).
Families are different, as are PIL and our own parents.
And for all of those saying "we've raised children, you know?!" - yeah we do know, and some of you have done a really crappy job. If you're lucky, your children will forgive you in that case and never mention it.