In my family we gave different words to the different grandparents, but chose more or less at random. This made the words unique and therefore more useful. It'

In my family we gave different words to the different grandparents, but chose more or less at random. This made the words unique and therefore more useful. It's not an "issue" for parents, exactly, but it is an interesting choice because of how much less trodden a path it is. Would you both go by dad? Would one or both be daddy, dadda, or pop? Would you use first names or diminutives after a certain age?