This is by far one of the best pixel puzzles books out there. I can only wish that he would publish monthly instead of annually! The grids are mostly no larger than 30 X 30, with many, many in the 25 X 25 range, and just a few challengers bigger than 30 X 30. The grading of the puzzles from 1-5 are fairly accurate, so you can choose what level you feel like working at and have fun with it. Like all pixels, the smaller puzzles leave a little to be desired in the quality of the picture, but that's to be expected. The larger puzzles turn out pretty nice to beautiful in some cases, and the ones in between are pretty fair representations of some object, not too busy (like the Griddlers).
The only reason I took off one star is for the quality of the paper. It's not as bad as those terrible Griddlers, but it does have some problems. Fortunately, it erases fairly easily, but it also absorbs moisture from the air very easily, so ONLY use this as an indoor book (not recommended for taking to the beach or camping!)