I have used the Illumenoks for a couple of years now and have not experienced any problems out of them. I shot a doe and didn't get a complete pass through on her and watched the Illumenok go bounce up through the woods, walked right up to where she was laying b/c of the of the Noc. Pretty cool experience.
Kind of want to try the Easton Tracers. They sa they blink and are a whole lot easier to spot than the Illumenoks.