I'm new to really paying attention to flashlights myself, so I pulled up some PDFs, to see if I could figure it out.First, let's get some tedious pedantry out of the way. A COB (chip on board), is different from the other two. Where the XP-L and the XHP are single LED emitters, the COB is a group of emitters, stuck together on one board. You can have a COB that's made with XP-Ls, or XHPs, but you really can't compare the three of them on an equal basis.I'm going to link to the two PDFs that I found. Both are from CREE, I may be in a "gray area", forum-rules-wise, but they're for information purposes.If you read them, you may find your eyes glazing over, like mine did!Near as I can tell, the XHPs are brighter, as in, they put out more Lumens. You have a lot (a lot!) of choices of how "white" or how "yellow" those Lumens look.If I know anything from other gear-related forums, there is no such thing as an objective "best". If you're looking at the LED as the start of buying or building a light, I would argue that there are many other more important factors than the alphabet soup on the emitter. These include, but may not be limited to:CostSizeWeightBody materialIPX rating (dust and water "proofness")Carry method (pocket clip, belt holster, sling)Battery lifeBattery type"Throw" or "flood", or a little bit of both?And, if you're secretly an engineer, and you're just trying to get a feel for what CPF considers the "best", then I'm just gonna go chew on my foot, for a little bit longer.
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