I'm trying to decide between the A650 and the SD950. From various reviews and a lot of comparing full resolution shots under identical conditions (reviews at www.imaging-resource.com) the overall quality of the two cameras is very close. So that just leaves the features. The A650 is bigger, heavier, more zoom, and manual features (Tv, Av, M, etc). The SD950 is slimmer, lighter, and uses a rechargeable Li-Ion battery.
However, using the CHDK firmware (http://chdk.wikia.com/wiki/CHDK), shouldn't I be able to use every A650 feature on the SD950? Using CHDK, shouldn't I be able to use Tv, Av, bracketing, etc?
Assuming my understanding of CHDK is correct and that I would use it on either camera, what is the ultimate difference between these two cameras?