I've worked as a partner for some car companies in both the US and the EU, and I know for a fact that the firmware that goes into their control systems is very tightly controlled, requiring sign-offs from senior execs for design and feature changes. There's no way code this critical could have simply been dropped in by some R&D leads. No. Way.

Nearly every upgrade before El Capitan used to result in something getting messed up on my Macs. This time it was very smooth, and with the exception of one minor upgrade to Little Snitch v3.6, there was absolutely no problem with the video and image editing software I used day in and out. Photoshop, Capture One, Avid media composer, iMovie, Office 2011, VMWare, OpenVPN and a whole bunch of other software I use just work fine. That said, El Cap has still not solved the horrible bluetooth audio stutter issue that's plagued all our macs and bluetooth speakers or headphones for years now.

I used to work for a large US based Fortune-500 company for many years. There was a shakeup where the president of the company and many of his direct reports were taken out. The layoffs were slow and stealthy. We would see many really good employees being given average or bad performance reviews and subsequently being terminated for "poor performance". It gets tough if your boss himself is in CYA mode and looking out for his job - he won't support you. Still, having been in the workforce for many years, my team and I exited gracefully since you never know when you'll do business together later. In short, never, ever burn your bridges, not unless your company / boss was doing something illegal or criminal. Unethical doesn't cut it.