Is that respectable in music, though? At a certain point doesn't "if it aint broke, don't fix it" become detrimental? Amon Amarth was releasing the same album over and over up until Twilight of the Thunder God, and all their albums since TotTG have just been Twilight part 2, 3, etc.
Consistency is good, Kalmah and Hypocrisy are "consistantly" good, but I think it's not a good philosophy to have to release almost the same album over and over.
Bear in mind, I am not a Disturbed fan and haven't heard anything beyong Sickness and Believe so I don't know if they made the same album over and over so this all might not be applicable.