As someone who likes to get his hands dirty and understand the ins and outs of every little piece, letting go and enabling others to execute has been quite a challenge for me as I've transitioned in my career.
His approach has been one of frequently checking in, understanding my context and constraints, and consistently providing suggestions and alternatives whenever I felt stuck or backed against a wall -- it never felt onerous, forced, or superficial. I truly enjoyed my time with John, and would strongly recommend working with him.
I've always known that delegating is key to being a good manager, but John helped me turn theory into practice, challenging me to really embrace this concept and make it a part of my management style. This, along with everything from presentation skills, tackling difficult conversations, and countless other soft skills that John helped me develop have been invaluable for me.