in terms of 411as method of flying level - it may well be practical (or required - some procedures require a visual level segment after reaching the missed approach fix) - however in many cases it is not practical - why fly level along the MDA to the missed approach point if you know that you cant descend safely to the runway with appropriate rates of descent and speeds when you reach that point? in most companys i would say that it would be viewed very poorly doing greater than 1000fpm below 1000 feet.......