If you have to go to airport then airport metro is best..... 20 mins from new delhi railway station and u are at Airport avoiding unpredictable traffic of delhi and is very comfortable also.
Very poor design - very difficult connectivity to the New Delhi Railway Connectivity. Keep at least 15-20 mins to do the change if you have luggage and be ready to climb up and down the stairs!!!
Reopens after 6 months with speed reduced to 50-60km/hr and increased fare! Not worth for daily commuting! Will use it only when its absolutely necessary!
Extremely convenient. Saves loads of time and the headache of fighting through traffic. Must avail every time a transit from the station to airport or vice a versa.