Think the delay in light turning on is part of hygrotherm program. Like a house heater or AC; there will be a temperature range of a few degrees where it will operate before it kicks in. The ceramic heat emitters have longer life spans; so what you can do is replace the infrared with a ceramic emitter when it finally burns out.
To determine if ceramic is more efficient than infrared, would have to compare the two units over a period of time while monitoring electrical consumption with meter like kill a watt or similar. Good luck!