I'd rather have a "reliable" POS handgun and make sure that the BG can't sue me after.
When using a TASER you need to consider that it will provide the ride for five seconds at which time you hope that the BG will comply or run away. If not then you have to hit them multiple times to ensure your safety. This could be a situation of being between a rock and a hard place.
Closer to home, my wife asked me to get her one of the personal TASERs and I gave her the same answer. You will be fine for the five seconds but afterwards when the BG gets up you will potentially have an even worse problem because now they are pissed off. To solve this you have to hit them again to prevent an attack, in doing so you could cause more damage to the BG if they fall and injure themselves. This in turn opens you up to a lawsuit because you may have used excessive force and the BG can tell their story and now you are the one who has to answer for your actions.
The TASER does have its place and can be properly used under the right conditions to gain compliance but you need to consider what happens after...
As a note, I have taken a few hits with the X26 and am a certified TASER instructor.