Both are true. Personally, I don't have the energy to optimize my personal cash flow like this, even when it is a reasonable thing to do. But then I am employed again, with a steady income. I would use those 0% credits, and manage cash flow accordingly, if I were still self-employed so.

For reasons other then cash-flow, I wouldn't take a credit for things other then a house or true business investments (as: my company needs a credit as a way of financing).