Folks, if you've recently upgraded or renewed your annual club membership but it's still not active, please reach out to the BOD or a moderator. The PayPal system has a slight bug which it doesn't allow it to activate the account on it's own.
I have the exact same fixture as you and also had the XM 20K, were very blue but very slow growth as expected with a 20K bulb.
I switched 6 months ago to the Phoenix 14K and couldn't be happier. They still have a nice blue tint to bring out the colors, but the growth of my SPS took off after the switch. Would def recommend the Phoenix.
I've used XM and Hamiliton and prefer tha later. I've not used the others, so I can't rate them.
I suspect this is true for most people. If you tried all 4 bulbs, and ran each one a year, it would take 4 years to try them all.
So take the results of your poll with "a grain of salt". You may be getting results for what people are currently using, rather than results for which is best.