Some claim they can do an 8x8 matrix panel in a half hour and all 8 of them in 4 hours. However it took me about an hour and a half to do each panel and I took breaks so I only did 2 of them Friday night and 3 each on Saturday and Sunday. Then it took a few hours to do the final assembly.
I recommend you take your time and take lots of breaks. When or if I do another project like this I may allow myself much more time perhaps only doing one panel in a day.
I did not have any trouble with the solder joints of the individual matrix panels coming loose during the final assembly but I could see how that could happen if the pins aren't bent just right.
Stay tuned:)