A weird attempt to keep cashing in on the Nirvana name, Sliver: Best Of the Box is one of those compilations with a very limited fan base and no real reason to exist.
First, the entire point of the With The Lights Out box set was to clear the vaults of all the Nirvana B-sides, demos, and rarities, many of which fans already knew about but wanted in one handy place. The set did its job of completing the back half of the story started by the well-known quartet of studio discs released by the band. Cherry-picking the "best" (a subjective term at best) for one disc, then, seems an exercise in futility. The audience for this, it seems, is those who couldn't afford or didn't want to invest in a three-disc box set but still are curious about the band beyond the overplayed alt-rock radio hits.
Second, the quality of this music is vastly different from the Nirvana that has entered the popular canon. Many of these 22 songs are either Cobain solo demos or early band punk-stompers that skate by on energy and little else, like "Mrs. Butterworth," a 1985 demo of "Spank Thru" (when the band was called Fecal Matter) and "Clean Up Before She Comes." An inaudible demo of "About A Girl," a ramshackle take on Zeppelin's "Heartbreaker," and the aptly-named "Blandest" round out most of the pre-Dave Grohl material.
"Sappy" is pretty good, an early version of what would later be called "Verse Chorus Verse," while poorly-recorded solo acoustic sessions of "Opinion," "Lithium," "Smells Like Teen Spirit" and "Sliver" clutter up the middle of the disc. The finished but unreleased "Old Age" is a nice grab, but two demos of "Rape Me" undo the goodwill, and a band demo of "Heart-Shaped Box" is good for historical reasons but little else. The disc ends with three fascinating Cobain home demos from 1994: "Do Re Mi," "You Know You're Right," and "All Apologies."
Here's the thing: You would never know from listening to this disc that Nirvana was a global hard rock phenomenon responsible for co-starting a musical movement (grunge), helping usher in alternative rock, and elevating a screwed-up misfit into a musical deity and hero to thousands, if not more, kids just like him. Sliver shows a ramshackle group of dudes who liked to play punk rock, goof around and maybe, from time to time, explore something a little more emotional than syrup and poop. As with many backstage glimpses, this is raw footage that will seem jarring to those raised on the slickly-produced Nevermind, but it is the same band stripped to their core, and even if it's not always entertaining, it's honest in the way Cobain always intended.
That said, this isn't really music that fans – hardcore or casual – will need to return to all that often. If you're going to complete the Nirvana story, the box set is really the place to go, as it includes most of Sliver and so much more. Fascinating from a historical perspective, I suppose, but it’s not really a necessary purchase.