I have this Bluestar 5 star rated AC installed in my house for a year now and overall my experience with it is very good.
Cooling In terms of cooling it is good, it cools the room quickly to 24 degree C.
Service You get a couple of free services in the first year under warranty and I availed one of it and the service response was good, according to me. The service guy came the next day of booking the service.
Overall its a good A/C to go with.
P.S. Try to clean your A/C filter once in 15-20 days to get the best cooling.