Life has a rational surface, below which is the infinite gloop. The Cure have made pop songs that are fun as can be (and others that irritate as much as any radio-friendly hit), but Robert Smith was in direct talks with the gloop for a time. The result was 1989's Disintegration.
Previous attempts at a masterpiece were merely attempts. Subsequent albums, so far at least, have been mostly studied. He's some artistic distance from Disintegration, but perhaps it's a lengthy ebb-and-flow thing rather than a more simple decline. Perhaps one day he'll turn up with a work of equal stature. All I know is, since that album his music is more likely to involve teenage-targeted angst and affected cat yelps. Attempts to be honest in his lyrics are likely to reveal a spoilt perfomer, where the words of Disintegration help reveal the submerged gloop.
An expanded reissue can cloud an album's virtues, and the 20 rough songs do little more than prove that Smith had much of the detail worked out at demo stage. Fewer of those, with the remixed singles from Mixed Up instead, would've better complemented the original 12 songs. The live rendition of the album has a beautiful open sound, though. It may cause drowsiness if you listen to it immediately after a full dose of the master version, otherwise it's more than lively enough. (You can find another, inferior, live take on the album on the Disintegration website, along with another 20 rough songs!) The remaster of the core songs brings benefits, too. It adds clarity, particularly to the depths of "Prayers For Rain", while managing to preserve the original mood. The "deluxe edition" is primarily, though, a reminder that Disintegration is Robert Smith's definitive statement.