How do tasers work against an individual with heavier (winter) clothing?
Thick clothing and leather jackets can present problems for a Taser.
I'd think carefully about carrying a Taser AND a gun. If you shot somebody with your gun, a DA could easily try to question whether you used the minimum amount of force available to you. "Why did you shoot this guy with a gun when you had a "less-than-lethal" Taser available to you? And what if you're unfortunate to have the guy you taze die, either from the Taser or hitting his head as he falls? "I didn't mean for him to die!" Well, he's dead anyway: Negligent or unintentional homicide charges anyone? Wrongful death lawsuit?
Police have continuum of force training that corresponds to the lethal and less-than-lethal weaponry they carry. Most non-LEO won't have that sort of instruction that they can use to back up their decision.
Another issue on Tasers. You have to remember that a Taser can light someone up for five seconds at a time. Once the jolt stops that person is fully capable of physically resisting and fighting, and is probably pissed as hell too. What are you going to do with them then? Do you have back up and handcuff also?
Not saying don't get a Taser, but make sure you think it through before getting one. It's not all that simple.