This one is between 4.75-5 ☆ for me but I'm rounding up to 5. This is very well done and feels like classic John Green. It's not my favorite of his novels but it's definitely the most relatable for me and I would guess even more so for someone I love. 
I think Aza is a far better developed character than the others and I actually didn't like Daisy as a person much. Davis seemed cool and I wish we had seen him and Noah in greater detail. 
I really liked it and would recommend it. It wasn't perfect but it felt real and meaningful.