The reviewer should convey clearly WHY does he absolutely love the album, or why does he find it very good, or quite alright, or weak, or completely forgettable. Comments like "this is sonic heaven, the best album I have heard in years" without any further explanation why, are meaningless.
Also, although each album is supposed to be unique in its own way, similarities or references to other better known bands or albums can be welcome in practice to give you a clearer orientation.
I have bought quite a few albums based on super-positive reviews which after listening to them for several tries did not impress me at all. I should try to find now some of those reviews to see why did they mislead me. Anyway there's always a limit to the trust you can put on other reviewers' opinions, at the end of the day we are all different.