Dr. Rahal used to work with Dr. Armani, now he has his own clinic. Dr. Armani is a controversial name on the forums, because he works on younger patients and sometime gives "aggressive" hairlines, to which some people think might come to haunt them down the road. However, from just looking at results, noone would argue that Armani is one of the best doctors, especially for hairlines.
Dr. Rahal is a relatively new name in the hair transplant industry. well, he is making his way to the top of the top of the list very fast whereas he wasnt really known a few years ago. His results too are amazing, but make sure you see any doctor's former patients before committing.