I believe that if either one of them (doesn't matter which) were to leave the band, it would be more devastating for me as a fan than how I felt when Rob left. It tore me up when he left, but the band moved on. I don't think the same would happen if Glenn or KK left. It's both or neither for me!!!
They are so different, but they are at their greatest feeding off of each other. They, together, ARE Judas Priest!!!