CFs- Warm W.Light or Cool W.Light, Does it really matter?

Just curious if it really matters if you grow with warm white or cool white...A buddy of mine says he has tried both and couldnt tell the difference. He also grew with both warm and cool CFs and the plants still were just as healthy. The only thing we did notice was with the cool light the buds seemed to be a little more compact, but not much more than with the warm white light..

Any thoughts?

I would definitly go with the warm for the flowering period. They are rated at about 27K which is much closer to the spectrum that HPS put out. Hope that helps!