I am the very happy owner of a Librem 13 and a Librem Key, I also crowdfunded the Librem 5. I am very happy with the products, I love them very much. My big worry is PureOS on the Librem 5 because I had some issues with it on the laptop, it is currently running Ubuntu. To be honest I should give it another whirl, I was a complete neophyte to Linux when I that happened and maybe now I could use PureOS better.
Anyhow the point to this is: while I am very satisfied now, this was a roller-coaster. I ordered my Librem 13 in August 2017 but only received it in January 2018. Some of it is my fault, I got the TPM added while waiting for the order so it pushed me back, I got the machine though.
A couple months after receiving the laptop it stopped charging properly, after a back and forth of emails with Goran Stevanovic (this is where this really pertains to your post) I shipped the laptop back to Purism for repairs. They accommodated me very well, especially considering I live in the Canadian Arctic. It came back with the same issue and I had to send it back again, both times the issue was the power brick and not the Librem 13. I have been using it without a hitch since, it has been about 6 months.
I pre-ordered a Librem-Key and it ended up being shipped to Germany instead of Canada, a simple email asking where my key was solved the issue.
All in all, my purchasing experience hasn’t been perfect but Purism has taken great care of me and have so far solved all of my issues to my satisfaction. The laptop is awesome and so is the key.
Customer service 10/10 would complain again 
TLDR: Encountered issues but an email to customer service always solves the problem.