I only use green:
- When I'm making a meal and in the middle of it realize 'x' pepper would make a really nice addition, but I don't have any ripe ones, or
- At the end of the season when we're getting frost or a too-cold snap and the plants are about done, anyway. I'll pull all the pods that are not excessively immature at that point, or
- When my only option is grocery store peppers (I've never seen my grocery store carry ripe peppers outside of peak season.)
A fully ripe pod has had the chance to fully develop it's flavor, which can be amazing compared to green. Green is often grassy, which may or may not be what I want for a particular dish. (And most often is not, at least, not as far as the chile is concerned.) Nowadays almost anyone can go to their local grocer and pick up both a red and green bell pepper, which is a good comparison for all peppers. Green bell peppers are simply unripe. Do a side-by-side taste test, and decide for yourself which you'd rather eat on a regular basis. I'll take the red any day. Assuming you can get yellow and orange, try those at the same time. My fav is still the red, no matter what the variety, in part because they develop more fructose than orange or yellow.