I've just replaced a Pixma 2770, with a 6870, and I'm quite happy with it so far - seems to be as reliable as the old one was back when it was new - i.e. Canon quality doesn't seem to have degraded.
Which? The 6870? Possibly. I don't live in the US, and my requirements were: a3, network/AirPrint enabled, preferably Canon (due to the previous one working well).
Being a 'new model' didn't really factor into it for me, and older models of all sorts of **** are routinely sold here long after they're replaced by newer models in the US and Europe.