I stayed at Park Hyatt Chennai for 5 days in December 2019. I was impressed by the cleanliness of my room and of the hotel in general, and the extreme politeness and friendliness of the staff. Like everywhere in India some of the rooms are noisy due to the roads being noisy - however my request for a quieter room was respected by the front desk staff and I was able to change to a quieter room. (Tip: ask for an inside facing room if you would like quiet.) The beds were very comfortable and the room well laid out and modern with a nice outlook.
The rooftop pool is lovely and has a view of the "jungle" next door. The sauna, steam and hot bath were lovely and peaceful.The gym is great - well equipped with machines and pilates/yoga stuff.
It's a little bit out of the way for the heart of Chennai, but still conveniently located and very convenient for the airport too. The metro station is a 10min walk (very walkable but not after dark if you are female).