I modded my PT EOS a few years back by swapping out the Luxeon star with an SSC P4 and that has worked well for me. I also changed out the optic for an IMS 17mm reflector and I love the headlamp as a result.
I've got 2 kids that still have the older PT EOS and Luxeon and I'd like to mod them to improve the efficiency. Just by changing out the Luxeon with an SSC P4 gave me roughly a double in output. Now the XP-G's and XM-L's are widley available in the same 20mm star form.
Do you guys know if there are any issues with replacing the 20mm star with an XM-L star. I know the led is bigger in diameter but I'm prepared to widen the opening on the reflector to accommodate. Am I going to run into any issues with focus, artifacts and funny beam pattern?