I love my Mammut headlamps. I've had reliability issues with PrincetonTek as well as being frustrated by the problems with the Myo series (I have a Myo 5).

The TX-1 bests the Myo series on all fronts (with a regulated main LED and smaller ones on the side, plus a blinking rear LED), and I prefer the TR-1 to my Tikka now (though the Tikka's still a decent series - not the PrincetonTec model I had a problem with, which was the Scout).