This will sound really stupid on my part but i need some expertise, I keep noticing all these leds out know For example K2, Q2 bin ,Q4 bin P4 lamp, ssc Seoul , Cree, rebel and i know there are others. My question is what is the difference, like which one is brighter than the other performs better, runtime etc. I understand about crees and how there brighter than luxeon's and how they have about the same runtime but are brighter. Just wanting to put my thoughts together so i know what i am buying most of the time?