The 150 is much better than the 40, no doubt about that. The only benefit the 40 may have is higher resolution in good light. Still, I am considering the camera that I can use both for paid jobs (should look professional) and for home videos (should be rather small). The HMC40 fits the bill size-wise and feature-wise, but I know that if I buy it I will be sorry for not buying the 150.