TNG is floundering. It's a excellent thing that they are trying to bring us quality SF stories, but the writers just aren't up to it. We had a couple of the best episodes ever, but they were unfortunately padded out with a lot of dross.
Part of the problem is that the same writers and directors appear episode after episode, series after series - and they still can't get it right!
The other disappointment is that even after three years, the Enterprise and her crew don't seem to be going anywhere, or achieving anything. There is no overall plot or theme, and continuity suffers for it.