I can tell you right now, I don't intend on buying the K2 Kroma. It sounds like a nice light, especially to have a TIR optic with 60 lumens, running for two hours, but the $300 price tag makes it hard to justify for me. The only thing the Kroma's got going for it that could justify the price is the combination of both red and blue 5mms with a Luxeon designed to throw... and it's multiple stages of light, but I racked my brain and couldn't come up with a single good reason as to why I want blue leds... or even red for that matter. It's a fantastic idea, but the K2 is really a specialized light, and if you can't think of any good reason to have both red and blue LEDs, then it's not worth the extra cash over the A2. At least, that's the way I see it. The K2 is about the size of the U2, which by itself is a beautiful and "small" light, but compared to other Surefires like the A2 and E2e, is pretty big.
What I'd really like to see is a stripped-down version of the K2 (obviously not with the same name) that is just the Luxeon with TIR optic and two stage. If the first-hand accounts of the Kroma reflect the final version, the 60 lumen TIR optic beam would be quite different in comparison to the L2.
Don't get me wrong-- I think the Kroma is a fantastic idea-- but just not for me. If you've got money to burn, by all means, get a K2 Kroma. But I'll stick to my A2 Aviator, thank you, because it's slimmer and much more idiot proof. (Yup, I'm an idiot... I like simple lights.)