I can only speak for myself, but I’m not missing the savings based on compound interest. I’m just saying that you won’t realize near the benefit by managing this through a HELOC and some silly software.
Even if you wanted to keep an open zero-balance HELOC in case of emergency (like the purchase of a plasma television), you’d do better to put all your paychecks in a money-market account, establish a low-water mark for that account and pay all your expenses out of there including everything you can against your mortgage until it’s down to the low-water mark. Then rinse and repeat (i.e. re-fill and pay down).
The scheme hawked here is actually taking advantage of people’s lack of understanding regarding loan amortization and compound interest, making it seem like it’s the scheme that saves you money rather than simply choosing to pay down your mortgage (and instead the scheme costs you more).
