Best flat iron for African American hair?

I wanted to know what is the best brand of flat irons to use for coarse black people hair? I currently have a relaxer but am transitioning to natural because I know relaxers are not healthy for my hair. Even though I won't be relaxed I still want to be able to get my hair straight so which flat iron should I get? Preferably one with a warrantee just in case. I have a cheap walmart conair one right now and it snags my hair and doesn't get hot enough. I've heard the chi is good but breaks down easily, and I've also heard of people saying that they won't honor their warrantee. What about sedu? Is that one any good? Also if you don't mind could you mention how long you've had your iron, your hair type, and what you paid for it. Thanks!