I've been running Phoenix 14K for the past year and I really like them as well. I've used Giesemann 13K and 14.5K in the past and had good results with them too but with so many other variables I cant honestly say which is 'better'. However you can compare the output of two of the bulbs on Sanjay's site here:
http://www.manhattanreefs.com/lighting
Phoenix 14K PPFD=88
Giesemann 13K PPFD=126
... unfortunitally there doesnt seem to be a measure of the 14.5K.
AB 20K PPFD=45
This article is one of the reasons why Phoenix bulbs have become so popular:
Light Output of the Phoenix 14,000K DE MH Bulb Over Time
http://reefkeeping.com/issues/2007-04/ac/index.php
My tank with 14K Phoenix
