MadMesh, your 420EX does ETTL/ETTL 2 fine, as does the 550EX, it's in the camera not the flash. The 580 is a bit more powerful and a bit more efficient, and both it and the 550 can control the 420 in a wireless setup. The 580EX is what i'd buy, it has a 1 button pan/tilt, which would be great when i'm using a flash bracket. If you use diffusers or light modifiers the advantages of the 580 are mostly lost, but i'd still get it, it's not a lot more expensive than the 550 now.



