As was posted earlier in this thread, the Princeton Tec EOS and Petzl Tikka XP headlamps got high ratings from Flashlightreviews.com

Since I happen to own both headlamps, I give you:
More notes on the Princeton Tec EOS and Petzl Tikka XP headlamps

My DW and I went out to the local mountains (San Bernardino Mountains) for some hiking and such this past weekend. Some of our hiking was at night which afforded me an opportunity to put my two headlamps through their paces. My wife does not like night hiking, but she did well and didn't complain this time, a testament to the quality of the headlamps. In the past, she had used my first generation Petzl Tikka (just plain Tikka, ca. 2001). Note to husbands: it's worth investing in a second high quality headlamp even if your wife doesn't hike often. An unhappy wife does not a good outing make, and the second headlamp can always be added to a BOB or what have you.

Overall Remarks
Both the Tikka XP and the EOS are good headlamps. I found my EOS, modded with it's Seoul 1 watt LED, to be a bit brighter and and the quality of light a bit better (whiter). The EOS definitely has a broader beam area than the Tikka XP and is brighter at the edges of the beam area. The headlamps are comparable in size and weight. Of note is the fact that both headlamps fit well in the Petzl Poche (carrying pouch). I find attaching the carrying pouch to my backpack or belt when on night hikes gives me fast access to the light when I need it; beats the heck out of having to take the pack off and fumbling in the top pocket. The boost function (press a button and the light goes to high intensity for a brief period of time) of the Tikka XP is really nice when you want to take a quick look at a particular distant object. All things considered, I think the EOS has a slight edge, but the XP's red filter and boost mode tend to negate some of that edge. If Princeton Tec were to add color filter capability and a boost option, they'd have an even better headlamp on their hands. In my earlier remarks on this thread, I mentioned that I thought the Tikka XP was a bit more comfortable to wear. After playing with the various adjustments a bit more (strap and tilt angle), I find the two roughly comparable.

Summary of Observations
Princeton Tec EOS
Pros
-Whiter Light (note: modded with Seoul 1 watt LED)
-Broader Beam Area
-Brighter at edges of beam area
-More water proof (reputation, not personally verified)
-Lithium battery compatible
Cons
-No good way to add red filter

Petzl Tikka XP
Pros
-"Boost" mode
-Red (and other colors) filter compatible
Cons
-Not lithium battery compatible
-Somewhat more vulnerable to moisture
-Smaller beam area

Note: I didn't take either headlamp to the point of battery exhaustion, so I can't comment on the virtues (or lack thereof) of regulated vs. unregulated headlamps. As is typical, both headlamps didn't consume a lot of battery life. Both sets of batteries still tested "good" on my analog battery tester after extended use throughout the weekend. The battery life of the Tikka XP according to the specs on the REI website are vastly superior to the EOS, but the EOS is regulated and the Tikka XP is not, which perhaps is an "apples to oranges" comparison. I make no attempt to address such issues in this post.

My DW and assistant headlamp tester.


Disclaimer: I am not affiliated with any manufacturer, retailer, or other related firm of any of the products discussed herein in any way, shape, or form, nor do I have any financial interest in said products or their purveyors. I's jus' a bro' sharin' muh experience. Got it?