Lightning may be harder to block, but it can be redirected, and normal fire is quicker to generate.

That's another good point. :P But I think when the lightning does hit it's a more deadly blow and it does more damage, however her blue fire is really intense too.

I agree that lightning is more deadly when it does hit. However, fire is enough to kill someone, and my main point is that it's harder to see coming and lightning takes time to generate, leaving one open to an attack for a few moments. I think that Azula's lightning is more powerful and intimidating, but her fire is just more efficient in battle.

That makes sense. The time to generate it makes it harder to actually land the hit and such. Nah, I get your reasoning. She's definitely quick with her fire. At the end of the day though, both are deadly in the hands of Azula.

They are both dangerous, to be honest

^