Two questions about the Philips LUXEON Rebel:
1. Are there any flashlights using this emitter other than Zebralight?
2. If not, why not? What are the negatives to it? I'm particularly interested in the neutral white tint of the one in the Zebralight H502d.
Aren’t the Maglites equipped with Rebels?
Some of the C and D size Maglites used Rebels. But they have switched to XP-E or XP-G now. Some of the old Fenix models used them too. It’s kind of old technology at this point and not as bright. Some people liked the tint, but you can get Crees in different tints too.
Try an xml U2. That is pretty much pure white. No extra hues or anything. It looks amazing on a white surface, and the colour rendering isn’t bad.
I bought quite alot of these and have used them in several lights with good luck. They are older technology but I like the light they put out. I use the 4500K Neutal White mostly. Build one into something… I think you’ll like it. We just did 18 drop ins for a guy a couple of weeks back for some little cheap lights he bought and the little junkies were pretty impressive when we seen the finished lights.
Dan.
Thanks!
How does one find out the CRI of an emitter?
Look up the datasheet. That gives what information the manufacture has put out for CRI. A quick google of the Cree XM-L datasheet gives:
Cool White (5000k-8300K) typical CRI is 65.
NW (3700K - 5000K) typical CRI is 75.
WW (2600K - 3700K)typical CRI is 80.
Cree also specifies some WW with minimum CRIs of 80, 85, and 90 respectively in the datasheet. I haven’t seen them out in the flashlight market though. The flux bins listed for the 85 and 90 are S4-S6…way less then the U Bins in CW 
I have a Maglite XL100, a Fenix E10 and a Maglite 2D LED with Luxeon Rebel emitters. Maglite’s have a nice cool white tint, that is nowhere blue like a Cree. My 3D Led (Cree XPE) and 2D Led (Rebel) can be easily identified by looking into their tints. Rebel has a much nicer, and neutral looking cool white. The same applies with XL100 too. Though, Rebel in XL100 looks to have a bit more magenta tint in the beam. It may be all because of the reflector or slight tint variances. Again my Cree XP-G Maglite XL200 is much much bluer than my XL100.
Fenix E10, on the other hand, has a very very nice neutral tint with a really nice CRI. I have nowhere read Fenix saying E10 has a High CRI emitter but it definitely has a light showing the true colors. I had been using this light as a bedside light to match my sock in dark mornings 
It is a pity E10 really was a limited edition and we can’t see it on the shelves any longer.
Rebel’s are good emitters for small lights and small throwers. I don’t think they give any better throw than a Cree XP-E but their tints at low currents make them attractive.