I have a Shack clock and GPS module from the first batch. It has been plugged in and running since I built it (not long after it arrived). Other than an occasional rare power failure it's been running non-stop for a lot of years. I had to swap the GPS module out in December 2019. There were no more "blinken lights" to be seen on the GPS. I build the cables from the GPS with the same DB9 pinout so I just plugged in another one and it's back online. I haven't done any troubleshooting on the original GPS module but I suspect that it won't be hard to fix. How long has QRP Labs been around? The clock has a lot of hours on it.
All things considered, I'm pretty happy with the lifespan of my clock(s).