Calculate out the balance transfer fee as an APR. It'll probably work out to roughly 3% fee = 8% APR or something like that. Cheaper than a 20% loan.

So if you have 2x 10k balances, and you reduced your 401k contribution by $10k a year that means you are on track to tackle half the debt this year, and with 0% sure you are paying a fee but the majority of your payment goes to the balance. Sounds good, you are on the right track. Sometimes it's best to look at the big picture.