I'm relatively new to McGizmo's lights, but my observations on the Haiku compared to some of his other lights are as follows:
vs. Ti PD-S
I'd says throw is about the same, but the Haiku has a broader beam. The Haiku is definitely brighter. I think PrecisionWorks measured the output to be about 180 vs 120. My particular Ti PD-S has a warmer tint (vanilla cream?) in the center, but cooler on the spill. The PD-S also has a very slightly smoother beam (it's hard to improve on perfection). The Haiku's beam is smooth and even throughout and is very neutral in tint. I would say I get better contrast and definition with the PD-S. The low on the PD-S is just marginally useful, but all three levels of the Haiku are well spaced, although I would have preferred the medium to be around 65lumens instead of 35. And of course, PD vs McClickie. I personally like the PD, but the McClickie is soooo easy to use. My wife cannot operate the PD due to strength and also she gets confused about the twist head for constant on vs push tail for momentary. No confusion with the McClickie.
vs. LS20
Low on the LS20 is cooler in tint, but more useful due to the flood. This is very obvious when in comparison to the PD-S, and not as obvious when compared to the Haiku due to the wider hotspot. Still, the LS20 has the edge on low. High on the LS20 is great with the tight bright hotspot and very smooth beam, but still on the cool side. The Osram is still smoother than the Cree in the Haiku. The Haiku has just the faintest inkling of the Cree ring, perhaps best described as a Cree shadow. Hard to notice except on a white wall, and even then, I had to take a few minutes to convince myself it was there. On high, the Haiku blows the LS20 out of the water, hands down.
vs. High CRI AMC Mule
What can I say? The Nichia has a great tint and CRI, but it is only useful indoors and close range outdoors. I wouldn't go hiking with just the mule. In and around the house, the light weight, compact mule is awesome. The Haiku is too large and heavy for my pj's or shorts. Both have detectable PWM on low and medium, but it's not bad.
Overall, my favorite combo is the Mule + PD-S. For a single do-it-all light, the Haiku is McGizmo's best in my opinion. I would even say it is more useful than the LS20, except for the fact that I personally like the PD. My opinion is that the Haiku is the best general use light that everyone can use and like. I can't think of anything that anyone would complain about (other than cost). The 3 levels are well spaced, beam is smooth, good balance of throw and spill, tint is neutral, not too big or small, McClickie is smooth and easy to use, and the machining is flawlessly executed. Just my thoughts.