It's a bit surprising that they put so much effort into security for the second microcontroller from a young consumer-oriented* company. My first instinct was to distrust it's security, simply due to lack of experience. However, the "experienced" vendors' secure micros have lots of known security bugs and, more crucially, a demonstrated desire to sweep them under the rug. Two security architecture audits, a $10k bug bounty, and designing a board for glitching as the DEF CON badge shows a pretty big commitment to security. I'm curious about how the Redundancy Coprocessor works. I still wouldn't be surprised if someone breaks it, at least partially.
* By perception at least. They have been prioritizing industrial users from a revenue and supply standpoint, it seems.