I had a transfer in Concourse D (Gate D37 to D4) yesterday. The walking to immigration was very long (I did not do timing); I passed the immigration quickly by using the Mobile Passport Control (CLEAR Pass App). The waiting for luggage was more than 30 minutes because half of the passengers on my flight were waiting near carousel. I went upstairs to use Pre Check on Checking Point #1. The amount of walking back and fourth on Concourse D was huge. I only spent 25 min at Flagship lounge and took train to D4 afterwards and arrived at T-20 min for my connection flight. My total connection time was slightly over 2 hours. I could save 5-10 min if I traveled alone (but I was not).