If you'll have the money to pay off your credit card debt within a month or two, you're probably better off not bothering with a balance transfer. That's because the transfer fee you'd have to pay would probably outweigh any interest that would accumulate during that time. But if paying off that debt will take three or four months, or longer, your interest savings will probably more than make up for the fee.
If you take advantage of a 0% balance transfer offer to aggressively pay off what you owe, there's no real downside. The money you save on interest can instead go toward eliminating the debt even more quickly. But if all you're doing is "parking" debt on a 0% card and paying only the required minimum without a plan to significantly reduce what you owe, you're only treading water. The 0% period will run out and you'll be right back where you started.