From what I understand, Marvin Rush preferred the softer look in his photography, which is why everything doesn't seem as sharp and crisp as the earlier seasons looked. He'd often use a diffusion technique. Just watch "Time's Arrow" and you'll notice all of the San Fransisco scenes have an extremely soft look to them. The same kind of look can be found in films like the 1978 SUPERMAN. Rush never went to that extreme in his Enterprise-D settings, but you can notice he'd take such liberties in other settings such as the Klingon interiors, Romulus, and many other settings.
Yes, I spotted the diffusion in Time's Arrow from day one - clearly an artistic choice in that episode. But, having watched a few episodes from this season now, even the (relatively) sharpest scenes are quite obviously softer than most of what's come before.
I am now moderately disappionted in the technical presentation of this set, but understand it may have not been avoidable.
Still, as I stated earlier, the boost in contrast and colour is a decided improvement on the pitiful S5 DVD's.