Only flown in Prestige (or whatever it is called=business) LHR-BOM - service ok and the 777 in top order but five years ago - it was newer then. Quaint wine service - bottle and glass bought to my seat and poured in front but all very slow.
Domestic service is ok - 737-7/800. There are those who say Indian airlines are less safe- they may be marginally so but not so significantly that it would influence my decision.
I don't like stopping myself when the sector length is only 7.5 hours out - 9 hours back. If you travel jet Airways you will be with other Newmarket customers and if things go a bit Pete Tong that may be an advantage