Gargraves seems to be known more for it's flextrack sections that allows you to bend any radius curve by hand, although it takes some basic skills. Their rails have a lower pair of flanges that ride in grooves cut into the wooden ties. This isn't seen if the final trackage is ballasted.
Ross, while known primarily for their high quality switches, seems to offer mostly sectional track. Like their switches, they fasten the rails to the top of the ties in a more traditional spike manner. Thus, their sectional track doesn't have the rail flange below the surface of the ties. Not sure if they make flex track.
I always assumed that Ross was a little more $$ across the board so people would spend it on their switches, which are critical, but save on the regular trackage where gargraves was both good enough and offered the flex sections.
