About the post of beware of the so called experts.
Even in my early days of setting PID loops (before I was taught) I never found it too difficult, usually if it could not be tuned it was a problem with the design of the system not the PID controller (I refer mainly to direct steam injection into product in-line one of the hardest to control).
I have worked on many systems including ovens, speed control, heat exchange in-line injection, I worked with an expert in steam injection who designed a well known system, used extensively in food production controlling in-line cooking to +-0.5 deg C, this system used pressure & temperature control on the steam (one of the hardest to set-up).
Just because some people out there have no idea dosen't mean we are numbskulls.
I am currently working in a food envioment where we have 22 plants producing food using probably more than 50 pid control loops, most of these are using PLC based systems, incidently I have set up all of these, so I think even by default I can be called a sort of "Expert".