As usual AirRabbit speaks words of wisdom. Back in the late 1980s I spent time with Boeing as they were developing the new CRT displays for the PFD on the Boeing 747-400. They experimented with a number of different presentations, round dial, tapes, different sizes, different colours, etc. and also the scales and sensitivities on each element of the displays and the relative sensitivities between them. The pilots involved were given a number of flying exercises, short routes that involved multiple turns and level-outs, etc. all ranging in difficulty. Then we, and the Boeing engineers, rated our performances and discussed preferences.
Some of the displays I found almost un-flyable, others were easy and intuitive. The final displays used by Boeing on the -400 PFD I found very easy to fly. I liked the tape presentations for speed and altitude but found the VSI too small. I also very much liked the way the FMA information was grouped at the top, the way speed commands and limitations were displayed, the large central ADI, and the colours used.
However, the thing I found hardest was to shed my personal preference for the round dial instruments that I had used for the previous 30years. It is very hard to separate basic ergonomic factors from learned personal preferences that have become ingrained from years of training and use. I am sure there is a huge amount of research information on the interesting topics that are being discussed in this thread which AirRabbit could direct us to.