It's depressing looking at the lm/w efficiency of most of the screw in bulbs. While they are an improvement over incandescent and CFLs, when compared CXBs or Veros, they are awful. The best screw in bulbs I've seen are the Phillips or Great Value bulbs at about 103 lm/w, most are < 100 lm/w. I was somewhat excited when seeing the bulb PB posted, since it's putting out 2200 lm, but it takes 30w to do it so the lm/w is only 73. I've gotten used to seeing lm/w values of 160 - 200 in this forum, so I guess I'm expecting the same from bulbs, which probably won't happen for a few years. It'd be great to be able screw bulbs into a couple of the clamp-on lamps to use for side lighting or supplemental lighting - not saying you can't do this now since the bulbs will grow plants just fine, but they are not a very efficient solution as Tim has been noting.