Here's why I don't like the loan from your 401k: Not only are you paying 9% on the money you borrowed, but that money is no longer growing at ~8%. It's overly simplistic to say that you're paying 17% on that loan, but that should help you visualize what you're losing in terms of growth over time.
Thanks for the reply. I'm not 100% positive on this, but I -think- that the way it works at my company is when you repay the 401k loan, you're paying that 9% interest back to yourself. I just lose a fee for the loan (which is $75). I might be wrong. But either way, isn't that better than paying 34% towards a credit card?