I have recently gone with the pronounciation of Mah re oh, instead of Mair re oh. The pronouciation is generally split in the area of the country that I live in (Hudson Valley, NY), but 60-70% seam to say Maireoh. My aunt believes that it is because New Yorkers have a hard sounding accent. Which seams to go along with the reason why i like Mah re oh better.. as the a is softer, lower, and more masculine.