I find it interesting that the question is defined in terms of a dichotomy with "religious" at one end and "atheist" at the other.

I think it's very reasonable to consider atheists to be religious. Like other religious people, they believe (sometimes strongly) in a proposition that cannot be tested, and some are quite willing to proselytize for it.

The opposite of "atheist" is "theist". And while many of the most successful religions are theistic (Christianity, Islam and Judaism, to name a few -- in alphabetical order) others are not. Where do Buddhists fit on this continuum? How about agnostics?

I think the correct opposite of "strongly religious" would have to be "entirely indifferent to religious ideas". Otherwise, the discussion almost invariable turns into an argument between different types of beliefs, rather than a comparison of belief with non-belief.