In comment to the streamlight recoil thing... I wouldn't say it's true in my case, I use the TLR1-C4 model on my carbine, pistol and my shotgun. never had a change in output from them.

OTOH, I have broken a couple of surfire X200's and know a few guys that have broken theirs as well, surefire replaces them, but hey - once the confidence is lost you just dont get it back.

I do carry, exclusively, streamlight flashlights now. The rechargeable ones and the battery powered ones - they just dont break and they are SUPER reasonable. Lately I've bought their little military style light with multiple color LED's in it. Tried to abuse mine a bit, and it doesnt' burp. Multiple levels of white.blue.red.green and strobe function and they run on AA's.

There are, in my experience, occasional problem with ALL heavy use flashlights - the biggest questions to answer are:

1. Will the manufacturer replace them no questions asked (yes to streamlight and surefire)
2. Can I buy spare parts in case I break them and need them NOW. (again, yes to streamlight and surefire)

They serve a HUGE segment of the public safety market and with that size market they just dont mess with you on warranty claims - and the added benefit of local uniform supply stores carrying repair kits for most of their stuff. Usually it's a switch that wears on on a streamlight, or your lens gets scratched and yellowed and they replace it no charge and hand it back.

Can't get better than that.

EXCEPT for the nifty new light in my arsenal. The 5.11 "Light for Life"... It doesn't use batteries, it uses a new type of capacitor and recharges (I am not kidding) in 90 seconds from a full discharged state. I got the medium one (came out last year) and I am thinking I need a second one. A bit larger than the Centurion from surefire, but slightly smaller than a 2D cell maglite. If the other guys start using capacitors (I think they will within five years) then the flashlight game is a whole new deal, it will revolutionize flashlights the way LED's revolutionized lighting.