DE Bulbs: In your opinion, (and experience)

[Denis]

I just switched to 14.5k Giesemanns from 10k Ushios, I'm very happy.
Much whiter than Ushios.
I'm still using VHO actinics for the extra color.

[Jaws]

If you want intensity and blue color you have to go with 400W bulbs in my opinion. I'm running four 250W Geismann 20000K DE bulbs on a six foot tank and although I love the color, I miss the shimmer of the 10000K Geismanns. I was warned by my LFS too. Not that I don't like the color of the tank right now but I think 14500K bulbs would have been better. When my lights run out next year I think I'll upgrade to 400W 20000K's. They've got a nice blue color without losing any intensity IMO.