Purchased to replace a dryer I had owned for years. I am aware of newer models which promise so much for so much money.  For myself, I am a white woman with naturally curly hair.  I spend less than 5 minutes drying my hair.  Guess I'm a lucky one, I can use the diffuser to remove most moisture in under 5 minutes on a warm temperature setting, then set the curls using the cool temp setting and the "cool" button.
The dryer has all the bells and whistles I need.  3 different heat and blower settings. Ionic technology was an important factor I considered, and this dryer has it.  My hairdresser advised me the ionic piece was critical to ensure your hair is not damaged by heat.  All the other stuff you can buy, is fine I'm sure if you need it.
I didn't.  The only other thing I absolutely needed was the diffuser and once again--this dryer includes the diffuser as well as the concentrator, which I use if I want to style my curls straight.