If you mean is it the brightest mod for the money, then yes it is. No, the beam is perfect, but if you back off slightly from the tightest focus you get a usable round hotspot. I've been building and selling these mods for almost two years using Radio Shack bulbs and as far as I can tell, was the first to try the KPR112.
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Between this and my customer feedback (most of them non-flashaholics), the KPR112 bulb life can be fairly good if; you use it mostly in short bursts, and some bulbs just seem to last longer than others. I'm willing to pay $1.29 a bulb for this kind of brightness. (less if you buy in quantity) It's brighter than a 2C with 4x123 and KPR118 or 20W MR16 lamp, and equal in brightness, though not in total output to a Surefire P91 lamp. Not bad for $20.
Some of my other favorite cheapos are:
2AA Eveready Industrial with 3x123 and KPR112
" " with Surefire P90 or P91 Lamp
Dorcy Boss/Craftsman Tool light 4AA with XPR103 bulb.