i have three PT Corona's [see EDIT #3 below] and a PT Corona Extreme (both available from BrightGuy.com; both costing the same $47.95).
i find the beam color to be on the cool side, i.e. a slight bluish hue which is somewhat noticeable when "white wall hunting", but NOT objectionable, IMO, even for this use. however, i can't say that i notice any blue tint outside or even in use in a dark basement. of course, YMMV, as LEDs vary in regard to tint from manufacturing batch to batch. on fresh alkaline cells my Corona's all show more blue than the CoronaExtreme which shows almost none.
i can't comment on burntime as i don't really pay att'n nor have i done any burntime tests.
have seen plots of 8HI beginning at 510 lux [the tester's table shows 510, but his plot show ~560 or 570 lux] (on that particular light meter at 2 feet [don't ask me why that particular tester uses 2' instead of 1' or 1meter as is often used elsewhere]) running off of alkaline cells and a 50% of max value at about 6:00 hours and 100 Lux at about 13:00, the 8HI curve ending at about 18h at about 50lux.
the only other mode tested by that tester was 3LED HI. 3HI started out at ~225lux on the plot (275 lux in his table??? don't ask!) and showed a ~50% value at around 12h and crosses the 8HI curve at around 13h, but then continues to decrease linearly to ~50lux at 27h and his curve goes out to ~25lux at 35h.
both curves on his plot really didn't look to be regulated at all, IMO. these curves came from Backpackinglight.com, but i don't know if non-Premium members are able to view them (some of the website's content is reserved for paying members; i can't recall if the Corona review was among the "premium" content).
the CoronaExtreme version it is noticeably brighter (side-by-side unaided "eyeball" testing, NOT Lux/Light meter readings) on 8LED HI than the regular 3xAA 4.5VDC PT Corona - the diff is really quite noticeable though i would say that it isn't even close to being twice as bright - at least not to my eye.
the CoronaExtreme uses 8xAA cells in a 2x4 cell parallel arrangement. so, very long burntimes, and regulation is maintained far longer. even better, using Li primary AA cells give the best regulated burntimes for all four HI modes (i.e., 8LED HI, 5LED HI, 3LED HI, and 1LED HI) - this is true for both the Corona and the CoronaExtreme.
Mfr. claimed regulated output burntimes on the regular 3xAA 4.5VDC PT Corona is not too good on 8LED Hi as regulated burntime is only 5min to 30min, but it then runs unregulated for quite a while thereafter. other modes of the Corona run in regulation longer or so the mfr. claims.
i don't prefer the Corona for nighttime trail navigation since it generally fails to meet my personal requirement of being able to pick out faded, lo-contrast blazes on rocks and tree trunks from a minimum of 30' away. however, my age degraded (it's downhill to 100 for me), but otherwise normal, low-light vision ought to accept, perhaps, part of the blame for this.
other than this aspect, either Corona model is otherwise a very fine headlamp for lighting up a large area in front of me. when coupled with a small lightweight Cree/SSC LED flashlight, or an incandescent light that is used intermittently, either of which give much better throw than the Corona/C-Extreme, they form a nice combination.
the CoronaExtreme is sold as a BIKING headlamp. what i did was unscrew the "head" (they're identical on both models of Corona - pics are on BrightGuy.com here==>
http://www.brightguy.com/products/Princeton_Tec_Corona_Extreme_BIKE_Light.php) from the bike mount and screw it onto one of my PT Corona headband "head" brackets [after removing the standard Corona "head" of course; and i also remove the battery pack too. this converted it from a bike light to a headlamp - simple enough to do.
please let me know if i can try to answer any more questions for you.
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EDIT:
just checked - that Corona Review appears that it will be accessible to non-Premium members. here's a link:
http://www.backpackinglight.com/cgi...princeton_tec_corona_led_headlamp_review.html
EDIT:
re-read your Post. IMO, you ought to have no trouble walking on uneven terrain and be able to see 10' to 15' in front of you (i have used the Corona in precisely this manner).
the CoronaExtreme comes with a bracket+velcro bike helment mount. if permitted by your safety regulations, it would NOT be difficult to cut two very small slots in each helmet and pass the velcro straps through the slots, thus mounted the bike-helmet bracket included with the PT CoronaExtreme on a hard hat. also, the top/bucket strap of the regular Corona is removable if(???) that will help wearing the Corona under a helmet.
EDIT #3:
why three Coronas? one is kept "stock", so to speak. my second was purchased to make a very simple mod to, i.e. i cut the cable going from the battery box to the head and added connectors (phono plug on the box and phono jack on the cable going to the head). this allows me to use some home-made +4.5VDC remote battery boxes (with a similar phono plug) holding 2x3xAA (parallel-series arrangment), 3xC, or 3xD cells in my pre-CoronaExtreme attempt to increase burntime while still being able to re-connect the rear mounted battery box holding 3xAA cells as a b/u power supply if and when the home-made extended capacity remote power source runs down during a very long outing. the only area that i didn't often don't do UL backpacking in was in the lighting area.
note, i do this for many headlamps with rear headband mounted battery boxes. i use 1/8" aka 3.5mm aka 'mini' "phone" plugs and jacks on +6VDC systems and "phono" plugs and jacks on +4.5VDC systems. if using NiMH cells on a headlamp that can handle some overvoltage, then i can use (though i haven't yet) the four cell boxes (normally +6VDC with alkalines) and a phone-2-phono adapter.
the third Corona was initially purchased as a back-up (so, it's really the second Corona - chronologically speaking) b/c i really like this headlamp, and then it was disassembled to allow the CoronaExtreme to be mounted to the headlamp bracket/headband assembly.