Depends where you need to go in Delhi... If it's just about the hotel, I would always go for the Andaz nowadays. Outstanding hard product and very convenient due to proximity to the airport and Gurgaon.
However, if you want to have the better Delhi feeling I would rather choose the HR because of the location. I was there every two months before the Andaz opened in 2016 and in the meantime all rooms should be modernized and staff was always great.