I replaced 8 incandescent bulbs in two bathroom fixtures with these bulbs. Just the difference in the heat output of the lamp tells me that they are much more efficient than the old incandescent bulbs. I replaced the 60w incandescent bulbs with these 40w LED bulbs and I honestly can't tell any difference in brightness and they are very close in color temperature. The only thing I noticed when comparing the light from the side is that the LED bulbs oscillate for a split second before lighting up - this is imperceptible in the real world. Had to return 2 of the 4 packages of my original order as they were sent to me in an unsealed plastic envelope and arrived broken. I hope Revain learns from this and sends them in more appropriate and reliable packaging as the replacement bulbs did.