What is the rating range for Lazlo Polgar's Chess Endgames book?

I'm interested in Polgar's Chess Endgames book, but I'm wondering whether it is suitable for me because I found the 100 Endgames You Must Know Workbook a bit too difficult for me.

It starts off with 318 Elementary Positions (mostly king-pawn endgames), then goes on to Theoretical positions, Deflection, Decoy, Opening up a Line, Closing a line (interference), Opening up a rank, Opening up a diagonal, Closing a diagonal, Points of intersection, Clearance, Discovered Attack, X-Ray Attack, Chase, Force, Double Attack, Interpose, Pin, Stalemate, Self-Pin etc

It looks very comprehensive with 171 chapters! Is it a good book to get? How does it compare with other endgame books?

I never found a reason for evaluating a puzzle based on rating. Either you can solve it or you can't. If you can't, you should put it through a search engine and understand the solution. Doing this is better than putting the puzzle off until you are "good enough".

The funny thing about this is you are using Polgar's endgames. He is the one who said anyone can become a master. He didn't have a school of chess with hundreds of students taught by level. The Polgar sisters had to solve the puzzles without any order. Probably Sofia started out solving certain ones, and then Lazlo thought, "Let's see what Susan can do from those", then Judit helped confirmed a "Polgar order". But realistically speaking, what you should do instead is look at every puzzle and find a way to determine how difficult it is to you. Imagine you are Judit, you have two older sisters that probably did these puzzles (I have no way to confirming this but it makes sense) and you are not looking at ratings of them. You are looking to compete to get better.

I dabble in puzzles here and there, but I would prefer solving the puzzles on the board within a game. 

I am not asking for ratings on individual puzzles. I'm looking from advice from someone who has studied the book, and also some other endgame book(s), to say whether it is a good purchase or whether there are better or more effective options.

I have it, and I took a look at one puzzle right now (in the 500s). The puzzle was a good one to do as a "warm up". My main complaint about it is that while it was a mate in 3 essentially, if you didn't solve it you were still quite ahead in the game. There is no reason to expect less time as a need to know this one solution. You would win anyways.

This goes back to who wrote the book, how did they write, and what is the expectation? I view this as a way for training kids or anyone that needs more time to evaluate a position. However, if you are to play that position in a game OTB you would most likely still have 45+ minutes on the clock given classical time control. You would have the time to calculate out all the necessary permutations compared to an endgame scenario where you might only have 30 seconds on the clock.

Not very useful for normal game play, but it was fun to look at like a crossword puzzle or Jeopardy answer. 

If you find 100 Endgames You Must Know Workbook LP's Endgame book will be hard for you. It is a collection of positions, no instruction per se. If you do not supplement it with a "regular" chess endgame book, it will be like jumping into water to learn how to swim. Grab it if you can, it is valuable but you are not ready for it.

Silman's Endgame Course will be much more beneficial for you. You can cement your knowledge with Müller's Endgame for Kids.

If you still want to study endgame Nunn's Understanding Chess Endgames and/or 100 Endgames You Must Know series should be next.

Still not enough? Then Nunn's 2 volume work on Endgames and the Bible of all Dvoretsky's Endgame Manual should be your last instruction endgame books.

Müller's Fundemental Chess Endings, Speelman's Batsford Chess Endings are like Averbakh's Endgame Encyclopedia with lots of material and explanation. LP's Endgame is more like Encylopedia Chess Endings with no text. Geared more towards coaches or master players to practice.

This is a long and tedious journey but well worth your time.

Hopefully, someday someone will write a book how to use an engine to properly evaluate a position. Then we can take useful puzzles and learn those. No single book is going to be all good or all bad. You should not just reject Book A over Book B. Instead you should discern the good content from the bad.

Thanks, I am currently reading through Silman's complete endgame course so will keep going with that for now.