I've just got my hands on a 2008 1.6 TDCI and I can confirm that more or less the combined MPG on the dealers website is true. Obviously that depends on a lot of factors (speed, distance, load, air con usage etc) but for the most part I find it to be about right and I am still amazed how many times in one trip I get 99.9 to the MPG.
So in short. Yes.
I heard the scenic word as well from the other half and we are both glad we didn't listen because the CMAX is a deceptive vehicle in that it doesn't look that big from the outside, but its like the Tardis inside...
I find that the build quality is very good and the drive is an easy one and there's the obious fuel benefit of the newer TDCI engine.
It may seem pricey, but I think that the CMAX holds it's value a bit more than some other makes.
Hope this helps mate.
2008 (08), 1.6 TDCI Zetec Avalon