...If they were to make a red LED one, i assume they would use the same LED as the one in their other current red lights - the XPE...
This is one of the main reasons im waiting it out to get the H502r (which they hopefully do release) - largest angle of visibility without any hot-spot to shoot into other road users' eyes
Ahh...I see. I sort of think of the "502" designation as meaning an XML emitter, but I suppose one could think of it as the body configuration and the circuitry, regardless of the emitter. Yeah, that would be a pretty incredible package--very efficient, wide-angle red light. I'd buy it!
I bought the non-frosted H51r because I wanted the option of throw for other purposes, and I figured I can always put diffusers on. Sure enough, the glass diffuser disk from the 4Sevens prism kit makes a good diffuser when I want one.
But I also don't mind having throw on the rear of the bike. I ride on a lot of country roads, and I want cars to see me a long distance back. And it is mounted low, near the chain-stay, so when they get up closer it should not be right in their eyes.
In addition, I have a Quark RGB mounted at rack-level, for a much wider-angle hot-spot-free red light. Visibility is a life-saver!
Sometimes I joke that I have all those red photons pouring out the back in order to give myself a forward propulsion boost. They're not just safety lights, they're photon rockets! The trouble is that I have a TK 35 on the front handle-bars, pushing me backwards....