I am personally very happy with the Haiku in terms of its design and function. I won't belabor the details or justification of my opinion of it here. As most of you are well aware, one of the latest and greatest LED's is the Cree XP-G. I got some of these and did some bench testing as well as prototypes and felt it was worthy of inclusion in a design offering. After some time in Solid Works coupled with the bench testing, I came up with a XP-G Light Engine and a custom McR-17XP reflector combination that can be hosted by the Haiku.
Externally, the Haiku and Haiku XP-G are the same flashlight. They both use the 3S converter with a drive level to the LED ~600 mA on high and PWM reductions in duty cycle for medium and low levels.
The differences are inside.
Clearly the XP-G is a smaller package than the XR-E and it has a lower max drive current which is moot in this application as I am driving these LED's well below their capacity. The XP-G has a larger die than the XR-E and its apparent size is even greater as you can see looking at them from the angle shown in the image above. This lends the ability to collimate and maximize lux to the XR-E but the XP-G will typically boast higher flux based on presently available bins and the direction Cree appears to be going.
I had to alter the focal length of the new reflector to accommodate as well as optimize its geometry subject to the Haiku host and LED package differences.
The McR-17 XP reflector has a rear centering cup similar to that of the McR-17 XR but the cup on the XP is designed to host a 5 x 1 mm O-ring that in turn cushions the reflector above the MCPCB as well as centering it around the LED. The O-ring extends beyond the cup's lip to isolate it from contact with the MCPCB. I have also added further electrical isolation by putting some kapton masks over the solder and trace of the LED leads. which you can see on the light engine above. In theory, this tape is unnecessary but Murphy lurks...
I did some comparisons between a sample Haiku and Haiku XP-G which presumably are reasonably consistent across the populations of these lights.
The sample Haiku measured 138 lumens on high in my IS whereas the Haiku XP-G measured 185 lumens. The Haiku measured 3300 lux at one meter and the Haiku XP-G measured in at 2800 lux.
In terms of beam pattern, the spot diamaters are similar between the two. The spill angle of the Haiku XP-G is slightly larger than that of the Hakiu and this is supported by the consideration that the XP reflector has a slightly greater spill "exit angle" which you can verify by noticing that the diameter at the front of the XP reflector is larger than that of the XR reflector and they are the same length. The spill from the XP is noticeably brighter than that of the XR and that frankly was the driving force behind my decision to go ahead with this light. On a white wall, you don't see the rings in the spill of the XP as you do in that of the XR but you can sense a slight decrease in intensity in the interior of the spot when you view the overall beam including the spill. Whether real or illusion, as soon as you use either light to illuminate a target field and concentrate on the illuminated objects, you don't percieve any of these artifacts.
Based on the LED's I am using in the presently offered Haiku as well as this new Haiku XP-G I would state that Haiku has a warmer tint than that of the Haiku XP-G. Both seem white to me but in contrast, you can see a tint difference.
I don't have any plans at present to attempt meaningful beam shot comparisons as I am not confident I could produce reasonable ones nor do I want to take the time in attempting to do so. I prefer to leave the subjective comments and observations to you guys as much as possible!
In terms of run time comparisons, they would really be a function of the Vf of the actual LED's used in measurement and Cree LED's vary significantly enough in Vf with no bin information. Run time should be similar is about all I can say.
The Haiku's presently being offered are of XR-E Q5 flux bin and the first wave of the Haiku XP-G is of R5 flux bin. This first wave will be launched in the next day or so.
When it's all said and done, I personally don't consider the XP-G as a clear winner or next generation replacement of the XR-E. Both have their obvious advantages but short comings as well. Ultimately the application and intended distribution of light could well favor one LED over the other.
Based on my personal preferences, I consider the Haiku XP-G an improvement over the Haiku but not by any significant margin. My bias is based on the increase in flux and as importantly, how it is distributed.