I flew on Vistara on October 2024 when my morning Air India flight from Kolkata to Delhi (when travelling back to London Heathrow on Air India) got cancelled due to a bird strike and so my flight got rebooked in the evening on Vistara before then taking my Air India flight to Heathrow from Delhi. And I can say that the service on board was mostly excellent and definitely the service all airlines in India should be providing to passengers. The flight was on time without any delay, the food was quite tasty and well prepared, the seats were quite comfortable, the interior looked relatively modern and well maintained, including the toilets, staff were mostly polite, helpful & friendly, and I really loved the airline Wi-Fi, which allows you to use the airline's entertainment, flight map and even some other services such as flight feedback (something which domestic airlines around the world, and even domestic Indian airlines, need to take note and learn from).
My only minor issues with Vistara were that while the food was very good, the non vegetarian food ran out by the time the food reached my brother (who had to get a vegetarian dish) and while the seats were comfortable, at least for the short flight, the legroom still seemed a bit tight. But apart from that, I had a great time with Vistara and its a shame in my opinion that its now merged with Air India and no longer an independent airline. All I can say is that other Indian airlines should learn from Vistara and upgrade their levels of service so that it matches (or even exceeds) Vistara's and I also think that all airlines worldwide whether domestic or international should have a Wi-Fi system operated by the airline, especially the entertainment & flight map systems for domestic flights.