Im a 2. I like to put in Morroccan Oil in my hair pre-dry, then it takes me about 10 minutes to dry. Then I set my U-Smooth straightener to 390 degrees (even though it goes up to 450, but I did 450 for a while and it killed my ends). I straighten my hair by layers, and this takes me about 15 minutes. So the whole process is about 30 minutes for me. For you thicker, super-curly girls, maybe you need a flat iron that heats up to a higher temperature to make the process quicker. My hair isn't so thick so I don't need that high of temp. But the U-Smooth is an AWESOME flat iron and avoids frizz!
But if you need help knowing what temp to set your straightener check this out: Hairstyle and Flat Iron Tips and Tools: Setting Your Straightener to the Right Temperature