Len - the Megachrome 13K is exactly like the Ushio 10K, so you'll probably want some actinic supplementation. The Megachrome 14.5K is what you'd think a 10K should be, pure with with a slight blue tint. The Megachrome Blue is like a 14K.
Len - Very nice bulb and as reefnutz had mentioned, similar to a Ushio or AB 10k. I've had a chance to try both the 13 and 14.5k Megachromes and IMO, I prefer the look of the 14.5k.
Actually, you will get a chance to see one, it's the bulb I'm using over my nano in the buildoff.
Len - I have 3 of these over my 215 with no actinic supplementation. I am driving them on Sunlight Supply magnetic ballasts. The color is very even but the nice hints of blue dissapeared at about 3 months of usage and they seem to spectrum shift fairly fast. Nice bulbs but for the cost I think I'd just stick with Ushio's next time around.
I use the 250 watt DE 14.5 version and as stated by reefnutz it's a crisp white witha very light hint of blue. Next time around I am going to go with the phoenix 14K from reefgeek.
Ben - I put a 150W Phoenix 14K over my frag vat last month. It's bluer than my 250W Megachrome Blue, but still very bright. IIRC, the Phoenix 14K has the same PAR level as the Ushio 10K. It's priced low AND is Made in Japan! PHUKING AMAZING!
I was running them Len. Nice bulb, not too blue and too expensive. I just switched completely to the Phoenix bulbs (all 4 250 de´s(used to be 2 14 k and 2 20 k)) and after the burn in, I really really like them. The price is nice too, and the growth is really nice. I'll post some pics when I get home next week.