I ordered several items from my Society6 and Redbubble stores to review the quality. These videos provide more detailed info if you're considering purchasing items from my stores.
TL;DR: Most things are good. There was some inconsistency with t-shirt prints from Society6 and one issue with a notebook from Redbubble. I also noticed some of the pouches were not totally square. Overall though, I'm pretty impressed with the quality for this kind of digital on demand printing.