I have tried lot of restaurants while being in chennai for last one year. Though been to copper chimney only twice, I can still say its good. Though costly but its food is good.
To rate it I can give few points:
1.) Ambience -- Superb
2.) Quality of food -- Excellent., some dishes might not be that good but u know nothing is perfect in this world. So give them a chance to improve.
3.) Parking -- Definitely a problem, its chennai.
4.) Money factor -- keep money in pocket, its not everybody’s restaurant. They charge like five stars.
For me the service and food was better than 3 star hotels I had food in. Never tried south indian there but north indian food was really excellent.