I stayed at the Shangri La on a business trip with my colleagues and some of our international guests and we were all glad we did. The rooms were comfortable with a beautiful view (ours had a view of the India gate, president's house, etc). The lobby was always beautifully decorated with fresh flowers, etc, and very welcoming. The staff were very warm and helpful; they would literally give their all to ensure you get whatever you need when you need it and how you need it (apart from one or two who were well not as pleasant but I guess that's the flaw of human nature). The hotel temperature was also quite lovely - we could easily forget it was 45 degrees outside! No troubles with wifi in every room; very convenient and efficient too.
The breakfast buffet at Cafe Uno was AWESOME with staff that treat you like royalty! (the lunch and dinner buffet were not as lavish as breakfast but still not bad; there was also the menu option either ways). The Thai/Chinese/Japanese restaurant was also great as was the conference room we used subsequently - comfortable and suitable.
Overall I would say our stay at the hotel was truly 5 star!