I had though about getting a princeton tech apex and fitting it with an SSC P4 led. How would this work out compared to the browning?
Get a high cri SSC, and a smooth six degree. A higher cri offers better detail to the eye, so lower lumens may be needed. Then, since you have a narrow beam, you will be able to operate at much lower current rates than previously thought. So, make sure you have a rheostat, or I would demand at least a 6 setting controller.
The unfortunate thing about lights is you need side by side comparison, and I don't have the apex. I have one ssc p4 mod in a 8 degree rough reflector. Better color rendering than a lux 1, or any of my cree's, but no throw. You would need a smooth 6 degree reflector. Color rendering nill compared with the rebel in my Nitro Browning, .
The design of the nitro is no corona, since all of it is gathered to a tight super bright diamond shape around the hot spot. So the entire diamond corona is brighter than any 8 degree hotspot, but in something like 17 degrees, I am guessing. Also, on high, it is quite bright, as in, "are these other lights turned on?".
The unmodified design is an aspiring jean pocket lamp, run on one rcr123. My modified AA design, isn't pocketable. But it runs a whole day, and I can manually regulate current from 60 , milliamps to over an amp (though I never burst it much above 700 milliamp). It blows away the Coleman Cree xre, any on shelf currently. There is no contest at any equivalent drive level, unless you like a corona-coleman 3 AAA has nice, wide corona, just poor hotspot by comparison. Now, the Coleman xre with smooth reflector and more forward lumens at any drive level than the xrc, has an astonishing bright hotspot, even at 100 milliamps. But the hotspot is much smaller than the Nitro, and weaker in the reds.