After 3 weeks of working about 5 hours per day I am now 30% completed of the top left quadrant (the hardest quadrant). The pieces fit very well, but the problem is that many different pieces share the same or nearly the same patterns. A large magnifying glass must be used to confirm that pieces fit by examining overlapping lines or details or tiny gaps in the fit. The included large paper photo of the full scene must also be consulted after many individual piece fits to confirm that the pieces really belong there. Many times I had to remove pieces that fit perfectly after I could not find adjacent pieces to fit to them. In some areas the pieces are featureless meaning there are no lines to prove a fit. I would prefer more variations in the piece patterns so that not more than two pieces in the same pattern set (2 or maybe 4 in each quadrant) fit together on two sides. Do not mix the bags, because that will make it much more difficult. I plan to glue the entire puzzle onto my living room wall like I did with many other giant puzzles at my previous homes.
Update - On October 10, 2012, I fully completed the top left quadrant. I have been doing jigsaw puzzles since 1956. This was the hardest one yet. I like to climb mountains as well as do jigsaws and both give views as I progress forward. This puzzle is really beautiful and the painting depicted was well thought out by the artist. At one point I was having so much difficulty getting pieces to fit, yhat I considered quitting. Then i discovered a neat trick that is not explained in the instructions. The piece patterns in every column except the border, the two central ones, and the one at the end opposite the border repeat themselves from the left half to the right half of each quadrant. So if the piece you need on the right half is a duplicate of one already in place on the left half, you know what that piece looks like which makes it easier to find or to prove a fit. Now that I completed a full quadrant, I will photograph its sections, enlarge, and print them in black and white, and tape the sheets of paper to my work table for the next quadrant.
Update #2- On december 6, 2012, I reached the half way point. The fully completed top left and top right quadrants are up on my wall. Now I am working on the bottom right and I am finding this quadrant to be much easier than the other two due to easily identifiable zones that the pieces can be sorted by and few featureless pieces.