Other than my own experience, I can offer no physical proof that any type of grow lighting is any better than another. I believe much of it comes down to needs and preferences.
One theory that I do attest to strongly though, is plants that are bloomed under LED grow lights, produce more trichomes and often times produce them a week or two earlier than HPS or CFL. To be fair, I can tell you that it seems sometimes, LEDs can take a week or two longer to reach peak bloom than when under HPS.

Here’s a peek at 4 of the 6 girls in the Bloom-Room, under the Pro-Grow 400:

Marijuana grow tutorial for beginners.

Day 24 bloom - Aurora Indica #1

Aurora Indica #1 - Trichomes and dank aromas develop on a "hammerhead" top.

Aurora Indica #2, Day 17 bloom

Aurora Indica #2, day 17 of bloom. She pulls a strong Afghan phenotype from her heritage.

Mystery Sativa "Bebe", Week 7 of blooming

"Bebe" our mystery Sativa, week 7 of budding, continues to pack on weight, red hairs & trichomes

Day 17 of budding for this Blue Mystic

Blue Mystic "G" at day 17 of bloom.

Any open space we had last week in the Bloom-Room, is quickly being filed in by all 6 plants.

  • Aurora Indica #2 is very short & compact, as I could not get her to stretch at all, but her tightly node branches are filling in with fat white hair clusters.
  • Aurora Indica #1 is creeping along & filling in nicely, already very sticky, her sweet aroma only adds to her appeal.
  • Bebe, the mystery Sativa is filling in as her white hairs gradually redden and her branches swell.
  • White Widow #3 is stretching & growing & blooming, A very aggressive grower since beginning to flower, she may be a big producer.
  • Blue Mystic “D” is another big grower, a little slower to bloom than “G”, but a very big finisher.
  • Blue Mystic “G” will probably not produce half of what “D” will, but her appeal isn’t in her quantity, but her unique qualities.