The system is really effective, I wanted to work at a place where the cliche "everyone cares about quality" is actually true and I found it - devs test, designers test, I test, customer has the chance to test the latest build every 2 weeks so that we can check that our quality checks are aligning with theirs. It gets to be a game of 'can the devs get it past my checks' and 'can I find new ways to trip them up' which builds up confidence in each others skill levels.