the 5050 are brighter by spec.
but....
the resistors used might change that, as they both aren't getting 20mA as recommended in the specs of each.
I can't see them really being that far off from each other. I think it would be more about where the light is concentrated as using them for their use.
the 8mm leds are designed to be seen from a wider angle, as the 5050's are more direction focused..