Unless I'm somehow overlooking it there doesn't seem to be any such distortion issue with mine that I can see so far
I've already checked for dead pixels and very happy to see there are none, so that's really good.
Any other common hardware faults I should know about and look out for in mine before my return window expires?
None come to mind, but I wouldn't actively seek problems. Just use your device and if any problems are notified in your day-to-day usage, them return it.