Well, the way mine worked was that the monthly repayment figure was recalculated annually as I outlined (y.m.m.v.) and the savings account was used just to accrue some interest on the cash you were stashing.
Yes if you can overpay, and if it does take immediate effect, then that's probably better. However, you have to budget for regular overpayments; my way of doing it is a bit more flexible in that, if the excrement impacts the rotary air-moving device, you could use the 'spare' cash for some other purpose - rather than being committed to making overpayments.

Yea, 'decades' was a bit of an overstatement :-D (I think I only managed to knock just over ten years off mine).

Tell you what though: I was surprised at just how quickly my repayments went from "Shit - how much!" to "Shit - that's less than a round of drinks!!!"
(minimalist ..., Wed 16 Nov 2011, 11:24, Reply)