I won't review the series, plot-point-by-plot-point and character-by-character. I'm just going to state my overall opinion of the series.
It suffers from what us fen might call "Riverworld Disease". That is, it starts out with a very good novel, but succeeding ones become increasingly dilatory and pedantic. Sailing Bright Eternity in particular becomes a series of physics lectures at one point.
I'm fascinated by physics (majored in it for three years) but not when it's lectures in the middle of a novel.
An even worse flaw is the huge bloating of the series. The last three novels (none of which are short) could have been combined into one much better one without losing a single essential incident. Mind you, incidents would be lost -- but none are actually important.
But the ending would still be terrible. I boil it down to "But then the good guys are saved for reasons the writer defines as inexplicable." Annoying.
It's so disappointing mostly because I enjoyed the first couple of books.
Has anyone else read the series? I'd be delighted to get other opinions.

In the Ocean of Night

Across the Sea of Suns

Great Sky River

Tides of Light

Furious Gulf

Sailing Bright Eternity