I've been a size 12 since I was 18 and have narrow feet. Although I can often wear medium. Sebago is one of the very few brands that is too long - size 0.5. The N width is perfect. I changed 12N to 11.5N and am testing them.
Pros
Very comfortable shoes
Cons
The materials used in shoes may not be of the highest quality, making them susceptible to premature wear and tear.