The Pentagon LED series put out a nice bright light but distance is limited compared to the Xenon series. The other neat feature about the Pentagon LED is that is comes with a build in circuit board for peak brightness throughout the battery life. The LED will out last and Xenon bulb for weapon use and it's really a nice light for room to room type scanning. The Xenons do better for search and rescue type missions.
Having said all that, I would not buy just a head conversion. As the whole light isn't much more than just a replacement head. There are plenty of good dealers on the board that sell both LED & Xeonon lights.