I've got 2 girls, one is a snuggler (the oldest), one is not (the baby). My mom has helped to care for my girls since returning to work after the birth of each. The oldest wouldn't sleep in a crib or pack-n-play, she wanted to snuggle. Might have been that she wanted the comfort of being close to grandma while away from mom. The baby wants her space.
When the husband and I have taken vacation without the kids, the baby sleeps in the crib and the oldest sleeps with Grandma/pa. As long as everyone is getting the rest that they need (while mom & dad may not sleep as well having my daughter in there with them, they'd sleep worse worrying about her wandering the house scared), then I'm okay with it.
I was much closer to my dad's parents than my mothers parents. I think it had to do with the love I felt as a child. My Dad's parents snuggled with me whenever I was there. I didn't get that with my Mom's parents. All are gone now. I loved them all, but there's a special place for the memories I have of my dad's parents.
Keep that in mind...