Well, I'm very much skeptical about overrating albums. My ratings go very deep. Anything that gets a 90% or more from me I'm going to be calling an amazing album probably for the rest of my life (or my rating is wrong).
If there's a song on an album I don't particulary care for then that album is not worthy of a 100% because it's not 100% amazing all the way through. If there's something with the production or vocals of an album it will hold it back as well. I'm so through that I would even go far enough to say a shitty guitar solo or chorus would hold an album back from getting a 100%.
Not everyone is like me when rating an album, however, & I think there's a problem with that. Some people will listen to an album twice & say it's teh best album evar giving it 100% & the same thing happens with the 0% too. I honestly do not ever recall hearing a metal album that I hated so much I would give it a 0%.