Having flown via a few airports, I would like to share prons and cons of a few airports/flights I have used for stopovers:
Dubai (Emirates)
Good(Emirates terminal) - good shopping point, comfortable seating, plenty of eatries
Bad - Flying time to India, flying time to Dubai is equal to flying anywhere in India and stopover and India flight is an addon, a lot to walk if your gates are far away or if your plane is parked remotely
Airline - Good entertainment system, friendly crew, if lucky you can be upgraded(I was), Their 777 can feel a bit cramp, they fit 10 customers where rest fit 9
Amsterdam(Delta/KLM)
Good- plenty to do at airport, museum, eating, shopping, casino, a direct train to city center takes only 15-20 min
Bad- poor quality seating and limited bathroom space
KLM - Clean, friendly crewm good seat recline, on time
BAD- limited leg space, if you are tall dont fly them, mostly economy configuration, 747s they fly to India are old but better than their new A330s they fly to US. Believe it of now just before landing in Delhi the roof of the plane started leaking with water on the row I was seated in and Air Hostess acted indifferent
Brussels(Jet Airways)
Good- just a neat airport with limited shopping and decent seating
Bad- Limited shopping
Airline- good food, good crew
Bad- A330s, not a big fan of them
Singapore
Good- Plenty fo food, shopping, seating
Bad- not advised if flying to US or other side, long flights
Singapore Airlines- Remember to order Indian meals if you are not a fan of asian food, but good airline
Frankfurt/Lufthansa
Good- Well connected by train to entire Germany, plenty to eat, comfortable check in, Lufthansa has connections to everywhere in the world, smooth passport control
Bad- no free wi-fi, limited seating
Lufthansa- make sure to get your meals right, I was given a vegan meal cause they ran out of other options and I couldnt eat it. Check your aircraft, avoind old 747s as they dont have IFE.
New York(JFK-T4)/Air India Direct
Good- a lot of connections, a few shopping places and eatries, comfortable to get to, security doesnt take long
Bad- just a mediocre airport, nothing terribly bad, Immigration can be time consuming
Air India Direct- Great product, good timings, plenty of leg rooms, decent food, best if you are flying to US, Early arrival at JFK lets you have a fast immigration
BAD- Crew, I have had both good and bad experiences on my 4 flights on this sector
Washington Dulles
Good- Clean, fast security, plenty to eat
Bad- far from city center, limited connectivity, limited flying options, Passport control can be very time consuming, depends on your arrival time
Will be back with more, hope people find this useful.