Hmmm, I didn't see this thread until just now, so sorry I haven't chimed in here. These are the kinds of questions that I feel I can be of some use on... being that I specialize-in / study / teach interpersonal violence survival / counter-street-crime.
Obviously this topic has been brought up dozen of times per year here on CPF, and I'm not about to go into all the detail it deserves in this post. I did an episode on my Self-Defense Show podcast about this topic as well, if anyone is interested. (See the link below)
#1) Don't totally rely on anyone or any thing for your protection. Self-defense is about layers, and especially preventative / risk-reducing / awareness / avoidance / pre-conflict efforts. All of which you spearhead yourself, pro-actively.
#2) Be realistic about what a good, high-powered flashlight can do for you in the context of self-defense... and what it CANNOT do for you. It's not a magical solve all per se, but it can be a decent aid (especially to your observational awareness) in your self-defense portfolio.
#3) Before you go around cracking skulls with a "strike bezel", know the laws of self-defense in your area. Do you know what justifies using that "weapon" (as the opposing attorney is sure to frame it). When should you use it, and when will it ultimately get you into more trouble than if you didn't use it. (BTW, I never call it a "strike bezel"... I always say it's for "breaking glass in a overturned car" or to let the light peak out when I put the light bezel down on a surface... strategic wording that may or may not help)
#4) Do you have a backup plan if your light is malfunctioning? What if you don't have it with you, or it is inaccessible? What if it gets taken away from you and used against you? What if it doesn't have the desired result (maybe the guy is hyped up on PCP, other drugs, or just plain adrenaline)?
SIDE NOTE: All of this also applies to all devices intended for self-defense... pepper spray, stun guns, even firearms.
I could go on and on here , but I'll stop it at that, because I think you can get the drift. Carrying / using a device / weapon for self-defense is a messy topic with many considerations that each person must consider for themselves. There are pros and cons that need to be weighed by each beforehand. But the big problem (other than the criminals) is people want magical solve-all solutions that give them a sense of security that really doesn't exist.
Do I believe carrying a good high-powered flashlight will make you safer? For myself personally, yes... I've considered all the factors and I believe it's the best choice for me because of my background of understanding violence and my other training and many other things I won't go into. I carry a Dereelight CL1H v4 with an MC-E emitter driven at 2.8v off 2 x RCR123's with a driver that has only max and strobe modes. I keep it on me except when I'm bathing and I practice deploying it over and over. I use it as a part of my self-defense habits on a day to day basis. That's a lot to take on (some of which I'm not mentioning) but I'm doing it for that one day I may need it to be a part of why I was able to go home to my family alive.
P.s. My website has more about this kind of stuff under the VITAL Tour section...
http://www.VitalSelfDefense.com
Hope this helps... I realize I left some parts out and skipped over some things I could have gone into... I'm just to lazy to keep typing all this out every time we have one of these threads.