I think that there were two main problems with Sleeper. Firstly, I don't think they were ever sure themselves whether they wanted to be a classic pop band or a classic indie band, and the mish-mash of styles is clear here. Secondly, their main asset also turned out to be their curse: Louise Wener. She was someone who could always be relied upon to come up with a great quote or turn of phrase - the ideal rent-a-gob for the mid-90s, and she was a surprisingly good frontwoman at a time when Brett, Liam and Damon were the media darlings. That said, as a result, the other band members were anonymous to the point of oblivion, making the "Sleeperblokes" a focus for some (undeserved) derision in the weekly music press.
And they turned out some excellent witty pop songs in their time, most of which are included here - the "Get Carter" referencing "Delicious" always was a great tune whilst trying to be an indie-thrash, with later songs such as "What Do I Do Now" and "Sale Of The Century" showing a slight progression in sound.
To be fair, they probably split up at the right time - before it all got stale, old and repetitious (something certain other Britpop bands could and should have learned from). I remember Sleeper fondly, and most of what you need is here.