I bought and use a Librem 13, the smaller companion to the 15. I travel with it frequently and have run PureOS and Qubes on it. I have never had a single issue with the laptop. There was an issue with the stock charger I was sent but the laptop itself I’ve had no issues with. I frequently use LibreOffice, Firefox, Evolution, VirtualBox, Signal, Slack, and Standard Notes without any issues related to performance.
The system did struggle with the number of AppVMs I ran (4) while I was using Qubes and I believe that may be an issue related to the core count/clock speed of the provided processors. I did not bother to perform any analysis and moved on from Qubes. It was otherwise a seamless install.
Durability, since it measured either through a period of time or through intentional abuse, is a difficult thing to gauge for new products. I cannot speak to the intentional abuse aspect, I’m a user not a tester, but I can say that I have traveled across the United States from the West Coast to the East Coast and throughout the mid-West without a single incident. I have owned the laptop for 6 months. I have made roughly 20 trips with an average of roughly 1800 miles and a standard deviation of approximately another 400 miles. I hope you find those numbers useful.
And always beware anyone who seeks to influence thought through hyperbole, no matter whether they are “pro” Purism or “con”. Evidence, plainly and honestly given, is always the best basis for decision making.