Spot metering is my preferred metering mode on the Canon 50D. This allows me to nail the exposure first time -- 99% of the time -- by using AE-lock on my subject and applying the desired amount of exposure compensation. However, I find this too slow for some situations, so would like to learn to use one of the "full frame" metering modes (i.e. Evaluative or CWA).
I have tried using both of these modes. On the whole, I found Evaluative to be unpredictable. I found myself having to second-guess when and by how much the camera had automatically added exposure compensation. On the other hand, I found CWA to be much more predictable, but slower as it was still necessary to AE-lock and recompose for off-centre subjects.
It seems that Canon designed Evaluative metering largely as a replacement for CWA, and that by not using this, I would somehow be missing out on much of the ability of my camera.
How would I be better investing my time?
a) Using Evaluative metering and learning to recognise how it responds in certain situations so that I can second-guess it.
b) Using the much simpler CWA metering and learning to read the scene to determine the required amount of exposure compensation.
If only Canon had an "active focus point weighted average" mode, it would be perfect!