I just spot-checked those 4 episodes from my DVD set on my media computer and I don't see anything so dark that I can't see faces and such. Not sure what the problem is with your set (could your TV or computer not be calibrated for proper viewing?), but I don't think MPI has done anything to the master tapes/digital files that were used to create this and other DVD sets. In the Blue Whale scene, I can clearly see both Joe's and Carolyn's faces, not just their eyes. And now, of course, I am wanting to go back and start watching those shows again...but first I must complete the pre-Barnabasr DVDs...
Brian