When I went through the academy, we drew straws to see who in our group would be first to get tazed. I drew the short straw. I actually got shot. Everyone else got alligator clips. HOLY HELL. And if it's not bad enough that you bounce around on the ground like a fish out of water, then you still have the prongs in you.
I used mine twice when I was on patrol. Both times, they later made the comment that being tazed was the worst experience they'd ever had. And one of them had been stabbed. I can honestly say being tazed was a worse feeling than when a dog attacked me, though as stated earlier, healing time is alot quicker.