I also recommend RM's with the synthetic sole for aviation use by Australian pilots (pilots of other nationalities only with prior authorisation!).
RM's are surprisingly comfortable and are very good in sub-zero temps, in tropical heat and typhoon conditions. They are excellent in providing protection in wet/flooded conditions and in fuel spills. They provide superb rudder and footbrake feel and control. Furthermore, the block heel prevents the foot sliding up the rudder pedals during emergency braking.
They are equally at home and look very fashionable with slacks or jeans in the bar after work and they save carrying an extra pair of shoes in the flyaway kit.
When they finally wear out, send them back to the factory and they are completely restitched and remade with new soles for about $150...as good as new.
If they had been invented by the Yanks, they would have been a controlled technology export!