I'm on my second Pixel C, I RMA the first due to the touchscreen issues. This far, no touchscreen issues on the new one, and no WiFi issues but I don't think this tells me anything.
What's interesting is the first Pixel C I got when unboxed and updated, didn't include things like sheets, docs, keep ... Setup as new device. This time around they were installed. The first one also had the "Google Play Services needs updating" message but the second one did not.
Just more anecdotal evidence that perhaps Google is aware of some general early issues and hopefully WiFi as stated is one.
Posted via the Android Central App
My second one just now developed the touchscreen issue everyone has been talking about. The Pixel C has been idle on the charger for about 2 days and I used it for evermore testing today and it happened. Rebooting didn't help. Booting into safe mode fixed this. When I rebooted out of safe mode it was still fine. I think I've read this same phenomenon on here before. This is a mess. This though is most likely a software issue in my opinion.
I got the "google play services needs updating" on both units and both had google docs etc already installed.
Google is definitely aware of the wifi issue see the link above your post.

If these things are not rectified by Jan 21st (end of return window) they will probably see a flood of these things coming back. Mine included.