Re: best weapon mounted light?
I honestly think that if you are not a high volume shooter, the TLR is just fine. That's what we issue at my department. I think we have had one or two battery box issues since we started issuing them about 5 years ago. One of the females on my shift dropped hers, and broke the lense. It still worked just fine.
If you are a super-ninja shooter, I think the X300 is a little tougher. The mount is not likely to loosen up and come off either, which can happen on occasion with the TLR. To counter-act that, many people over-tighten the screw on the side of the streamlight.
The Streamlight switch is a little easier to use in my opinion. The X300 switch is a little stiffer to rock and get it to lock. But then once locked on, it is less likely to switch off in recoil.
They're both good lights. Right now the X300 is on sale on a father's day promo direct from Surefire. If you don't want to spend quite that much, the Streamlight is also very good, just not as bomb-proof. It is quite a bit less expensive, and still a very good light.