When I have looked at these in the past, all they offer is (false) hope. Insurance companies do not pay - that is how they make money. Generally, you have to sue them to get them to pay, and if you need to make a claim for this insurance product you are probably not in a good position to be suing insurance companies.
If you think you have found a good one, do one of two things: (1) Buy it and enjoy the warm soothing feeling of smoke in your posterior, or (2) Demand that they send you the actual policy -- not testimonials, not glossy brochures, not a summary. Demand a copy of the actual contract that they are trying to sell you (which will somewhere revoke all the representations made in the glossy brochures). Once you have a copy of the policy, read it carefully and you will see that it excludes every possible situation in which they might have to actually pay you money. As but one example, I am sure every single policy allows the insurer to choose for you the cheapest/worst attorney that the insurance company can find, so that hopefully you fire their attorney and they can cut you off (this actually happens, I have dealt with them).
If anyone thinks they have a good policy (again a policy - not a brochure), please post it or send me a PM. I am willing to be convinced otherwise, but until I see a self-defense policy that helps the insured, I'll happily call them all hogwash.
Finally, if you are worried that you might need an attorney - find a CRIMINAL attorney ahead of time and have their number programmed into your phone (you need to make the call after 911, and before the police show up and separate you from your phone). If you are involved in a SD situation- you need an attorney immediately (minutes count). "Whatever you say, can be used against you in a court of law." This does not apply to your lawyer, so he or she can speak with the police on the scene. Also, he can work to get witness statements/videos, etc. while you are locked in a police car. An acquaintance of mine is free man right now because video exonerating him was obtained by his attorney in this manner. Calling your wife to find the number of the insurance company, so that they can call some lawyer for you later in the week - does about as much good as asking your wife to call your friend to see if you can borrow a gun when someone is breaking into your house.