the newer ones say on the boxes, no warm up time, instant bright.

Mine don't seem to take that long to come on. Maybe it's because they're the daylight ones. I hate the dark so I leave one in the living room, one over the stove, plus led nightlights throughout the house(including the bathroom) constantly on. Through the rest of the house I just turn lights on as needed. My electric bill including two computers constantly going, water pump & hot water heater, electric stove & fridge, stand up freezer on the back porch plus everything is usually under 60.00.