I've got hydraulic discs on my bike, I love them. The next bike will likely have them too. What I really like is the shorter handle, less pull effort, feel of more control and lack of fade.

Are they necessary? Nope, not by a long shot, especially for me a mediocre cyclist at best. A good set of brakes of damn near any type will work almost as well.

So you will never know until you try.