I like the full hollow as it's lighter in weight and gives me a tactile feed back on what the razor is doing. If the angle isn't right or it gets stuck I can feel that and back up and correct where the larger heavier grinds wil just plow on through from momentum and you have to deal with the issue it left behind. So for me a 5/8 full hollow and I'm good, but I've never been interested in extra full hollow singing razors.