I found this quite tedious to complete. The trouble with large symmetrical pictures is that it's like finishing a puzzle, then having to go back and finish it again when you already know the answer.
I entered "symmetrical" in the search engine so that I can do these puzzles specifically. Some people like them. I don't know what all the complaining is about. If you look at the numbers in the margins, you can easily see that it will be symmetrical.