up to 10% -  waste of time
up to 25% -  if you get if for free, you may listen though it may hurt
up to 40% - only for the fans of genre
up to 55% - noting new, but it's not bad
up to 70% -  good CD with some revelations
up to 85% - very good CD
up to 95% -  sensational, absolute must-have
up to 100%  - magnum opus :)

Just remember that all the opinions and ratings are totally subjective...