Technological edge Tesla has seems to be relatively thin. The innovation is in good productization, PR, risk taking and bold business strategy. If I understand it correctly, Panasonic is the more tech-heavy partner (patents for example).

Tesla makes good cars with very low reliability and I see it as conscious choice. They add performance features and cool factors at the cost of reliability. Bigger car makers could have done the same but they protect their brand and bottom line. Tesla can't continue like this when production numbers ramp up.