Disclaimer: I have not been to Mumbai.
That said, I have a client who goes quite often (At least a few times a year).
He was a long-time FS goer until, a few months ago, I suggested he stay at the Oberoi or Taj.
We were going back and forth between the FS, Oberoi, and Taj...and somehow we picked the Oberoi.
Booked him in a Premier Ocean View. Double upgraded into a suite under a Virtuoso rate.
His take: "one of the best luxury hotel experiences I've ever had" and "made the FS look like a Westin, at best."
This is coming from someone who spends a few hundred days a year in 5 star hotels - hotels often discussed on this forum.
Take that for what you will.
(He's on FT and sometimes comments on this forum. I won't call him out, but hopefully he'll see this thread and chime in.)