Done. 1 guess.

Done, 4 guesses

I have no idea why I find the expert puzzles to be easier than the easy, medium, and hard puzzles, but I did this one with no greens and no guesses. I think perhaps it might be that one "gets used to" how a puzzle setter sets his puzzles, and that I have yet to feel as comfortable with Iron Sudoku's easy puzzles because I somehow am more comfortable with puzzles that make it easy to find "triples" and to fill in "missing numbers" in a row, column, block as this puzzle did ... (sigh) ... I first started doing Sudoku puzzles on a different web site (sadly I don't remember the URL) where the category (easy, medium, etc) was determined by the number of cells that were filled in initially.

Difficulty 49.

Done

done

Costa Rica is very nice.

I found this quite easy. Ng/1 correct guess

JudyHall - Your comment about getting to know a particular puzzler's style has merit in my experience. We have two Sudoku puzzles each day in our morning paper. One is ranked 1-5 and regardless of ranking is always simple to solve. The other is ranked by stars, 1 thru 4
stars. Most 1 star puzzles are more difficult than the 5 ranking puzzles of the other puzzler. Some of the 4 stars are extremely difficult for me. I find solving on paper much easier than solving on-line.

I am thankful that you find merit in my comment, KnightTime, because I often find myself wondering if I'm just imagining that different puzzle setters have different styles.

JudyHall - If you like really challenging puzzles get a book of puzzles by Frank Longo.