I have had the TK20R for about a month now. Output looks dead on manufacturer specs. The beam profile looks exactly like the very well defined profile out of the TK15UE the only difference being tint. My TK15UE tint leans warm while my TK20R tint leans cool. The light itself is built so tough it almost feels like you have a hammer in your hand. The voltage indicating LED beneath the side switch is very nice to have. Have yet to have a single issue with the light.