[Answered ]-Does using exists() and count() together make sense?

In the case that objects do exist, doing two queries is less efficient than doing one.

In the case that no objects exist, I can’t think why exists() would be noticeably faster than count().

So I would stick with:

c = Model.objects.filter(...).count()

One disadvantage of doing exists() first is that you have not set c when exists() returns False. This could lead to NameError if you’re not careful.