I found the purchasing and building experience with this board to be excellent. If I had been paying just a bit more attention, I wouldn't have soldered the angled box header to the wrong side of the board. Perhaps some great big letters on the silkscreen might have helped. In my case, even that may not have been enough. :-p I managed to de-solder the connector, but destroyed it in the process. One month later, new connectors arrive, and assembly is complete.
On my version of the P3 32x64 matrix (I think it came from AliExpress), the ribbon cable header is oriented so that it lays right on top of the 4-pin power connection, preventing both of them from being plugged in at the same time. I know I could just solder some wires on down low, but I'm evaluating some other possible workarounds. Anyone else run into this?
Brian was great at pre-sale communication. He answered all my questions promptly and was very thorough.
I really like the clock. I used it as the basis for creating an alarm clock for my wife for Christmas.
There are a few things that you should be aware of though. First, the documentation is not as complete as it could be. I had to figure out a few things on the hardware assembly (like the instructions are color coded to the sharpie marks on the component packages).
Documentation on the software side is also a bit lacking (where to get libraries, etc.). Also, the software, as provided, doesn't work. There are bugs in the alarm code, and other places that I had to fix. That wasn't a big deal for me because I was planning to write my own software anyway. I just used Brian's code as a template / starting point.
From a hardware design perspective, it would be nice if you could lower the intensity of the LED display a bit more. Maybe use a PWM pin for additional brightness control beyond what is provided by the display controller. Volume control on the speaker would be nice as well.
I also ended up designing a 3D printed case for the clock. It would be nice if one were provided. I'll post mine on thingiverse for those who are interested.