I really like my DB18- it`s bright, good looking, well made, has a real nice switch and the fact that it uses cheap common batteries is a definate bonus (and you can refill just one "barrell" if you`re short on $$$ and don`t need the full runtime). As for how far it shines? Well I`ve taken it outside a few times now, mostly round the garden but once down to the shop too. It really lights up the path infront of you quite far with its pure smooth white light, and that is where it performs best, but it will also easilly shine about 100ft or more, just spreads out and gets really wide and not so bright. Quite like bright moonlight. It`s never really properly dark here in Suburbia though but out in the middle of nowhere away from the city glow this light is going to shine fairly brightly enabling you to see quute far. Craig`s right of course, that a good incandescent is best for shining the furthest- keep one in your bag for those occasions.
Personally I think the DB18 would make a great camping/walking/hiking light. It would floodlight the trail ahead and you`d not fall over any unseen cliff edges or trip on tree roots that easilly!
I don`t yet own any of the Trek lights but they do look quite heavy and bulky, and of course then there`s that grip-of-death head switch too, though I hear you can take out an O-ring to make life easier. The DB18 won`t outshine the 19-LED Trek (probably no LED lights will at the moment!) but by my standards as an indoors person, it wins on style, functionality and versatility.
As Craig said it`s really up to you- how much do you want to spend? Perhaps you may think the $100 is a little on the expensive side for a LED flashlight- a SureFire costing that much would far outperform it in brightness and compactness but remember this light will last a lot longer on inexpensive batteries (not sure how long, if batteries were cheaper round here I`d miss another nights sleep and see for myself) and the LEDs will last a lifetime since they aren`t overrun, and won`t break if it falls on the floor. The flat profile is handy as an anti-roll aid too.
I like it.