Do you want a theoretical endgame reference book or something that tells you what the general principles for playing different types of endings are?
Silmans Endgame Course gets pretty good reviews, I don't know where you saw it was overrated. Its structured to take you from beginner level knowledge to Expert so I would imagine it fits your needs.
My favourite endgame book is Endgame Strategy by Shereshevsky. The examples are not broken down into Rook Endings, Opposite coloured Bishop endings, Knight v Bishop etc because the starting positions are based on strategic themes rather than the material left on the board but theres a great index where you can search for specific endings within the games like the ones I mentioned.
I have an old library of chess books from the '60's including Reuben Fine's Basic Chess Endings. It is an old McKay paperback that is falling apart and while still usable, it won't be for long and needs to be retired. It is also written in EN with which I am comfortable but is a bit awkward in these days of AN.
So I'm looking to upgrade to a newer endgame book in AN. Silman seems to be one to avoid as it's considered by many to be "overrated" so I'm looking at several others. My rating is below 2000.
Nunn has three books on endgames. One is Understanding Chess Endgames in a single volume. Then he has a two volume pair Nunn's Chess Endings, Vol. 1 and Nunn's Chess Endings, Vol. 2. And there is the book by Seirawan Winning Chess Endings and the advanced Dvoretsky's Engame Manual of which lesser players are warned.
I don't have any good way to review these books before I decide on a purchase, and I live in a relatively remote area with no local access to other players with chess libraries so I can't lay hands on copies for evaluation. So I have some questions.
I will eventually put Dvoretsky on the shelf for reference as it seems to be the final word. My question is among the other choices. Is the single volume Nunn book a condensed version of the two volume books? Are any of these in EN? (Although I am comfortable in both EN and algebraic, I prefer algebraic these days.) How does Seirawan stack up against either the single or two-volume Nunn? And at the risk of opening up a can of worms, are there others worthy of consideration?