The System76 engineers are culturally very aligned with the core values of freedom of choice, customization, etc. They build software with the larger ecosystem in mind, and in fact, I’ve never seen them build something only for their own hardware (even things that could have been just for their own hardware, like the system76 power management system, has extensibility built in).
That said, they also balance this freedom with a set of “opinionated” good choices that they test and support. If you care a lot about stability, it’s easy to go along with the “happy path” and get a solid, up-to-date system delivered frequently. Every time they upgrade new features or kernel, they go through a systematic quality assurance process on multiple machines–including machines not of their own brand. (I’ve contributed software/PRs to their codebase, and they’ve always sent it through a code review and QA process).