This is currently my favorite budget headlamp. BUT… it doesn’t have USB charging and I wouldn’t use it without modifications. Unless they’ve changed it since it was first released, there are no stepdowns, so it gets dangerously hot. With custom firmware, however, the Convoy H1 is awesome! It looks like the UI has been updated, but not sure about the stepdown situation.
“The (budget) King”… made better 
Ditto on the SP40 (review). Great headlamp for the price.