Many people in Mumbai spoke negatively about Delhi but we have found it to be as good, and interesting, as other locations.
They seem to think tourists don't want to see old Delhi, masses of people and chaos theory in action but 6 of 8 on our tour loved it.
Traffic is a laugh a minute in old Delhi with all vehicles willing to enter an intersection simultaneously even if it leads to an impossible letreset to unravel.
Interestingly we think there is a little less rubbish around Delhi, although it would still be a nightmare for clean freaks.
Rickshaw travel - when motorized options are pointless. We even had to abandon them at a totally blocked intersection.