Assuming one carries a balance month to month.
I use it exclusively. Pay everything I can with it ... electric, water, groceries, auto related ... I'd pay my mortgage if I could. Those are all expenses I'd incur anyway.
The rewards points add up pretty quick. I recently purchased a BRO AR10 using points.
I use mine this way too. I alternate between my bank CC and Cabela's. I've purchased two guns now with points.