Anything that takes the helmsman's attention away from piloting the boat is a bad thing.
I agree, display configuration is to be done in the slip, not underway.
The same reason why I like my i70s and the ability to configure screens to display the info I want front and center. Then one button press to change the data displayed. I usually have one i70 showing depth and SOG, (I also don't trust the paddle wheel for speed). The other shows wind info. When depth and or speed is critical one button press on each display and they mimic dedicated depth and speed instruments.
For the same reason quoted, I like the AP front and center. I think with the 2 i70s I get the best of both MFD and dedicated instruments, all front and center.
2. Since they are digital are they difficult to see with polarized sunglasses?
The i70 displays are very easy to see in bright sunlight. I have polarized sunglasses and can easily read them nav pod displays from the perch seats.
Is the wind direction/speed function on the Multifunction difficult to see?
Not at all. You can keep the screen simple, add data or mimic a dedicated wind display. Your choice.
You have many screen layouts and data sources to choose from which allows you to choose what is important and how prominent it is displayed. You can choose a layout that mimics the dedicated wind display or you can choose a layout that displays up to 6 fields of wind data.
My i70 screen for wind has a dial showing AWA, AWS and direction. It has 3 data boxes to the side that show TWS, TWD, SOG.
If I have guests/new sailors at the helm and want to simplify the screen for them, I switch (one button press) to a screen with the dial showing AWA, AWS and direction.
I had dedicated instruments and found the i70s much easier to read.