One thing to add. People need to recognize that the difference between the Shimano Blue and Yellow cleats goes beyond the simple angle. The location of rotation changes and that has a measurable impact that makes the potential impact on the rider more than we might expect based on the angle alone.
Pardon the rough drawing, but this is a rough shape and size of my shoe.
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The left side is the Yellow cleat with the +/-3* angles with center cleat rotation, that gives the horizontal heel displacement range.
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The right side is the Blue cleat with the +/-1* angles with front cleat rotation, that gives the horizontal heel displacement range.
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Notice how close the actual heel displacement is despite the different in Yellow (6* overall angle) and the Blue (2* overall angle). This means we only end up with a slightly reduced heel shift when we might expect it to be much smaller from the angle only.
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Notice that the biggest difference is minimal displacement on the fore foot from the Blue compared to the Yellow.
Just an interesting observation, not sure it really matters?