The Radisson Delhi is fine - a few minutes from the airport terminal. As long as your departure from Delhi's rail terminals isn't too early, you could stay here and get driven in after rush hour is over. Otherwise, a night drive into a hotel in Delhi / New Delhi would possibly be easier on anyone arriving from places with limited access freeways. BTW, as for information you have been given, GUWonder is possibly THE India guru hereabouts... and GUWonder's advice would always trump mine.

(It certainly looks like one is coming Gurgaon - Delhi, since if you have the right room at the Radisson you can look out your window and watch detailwork on the elevated freeway deck. That room could be a bit loud at times.)