What a disappointing decade and a half it’s been for fans of Paul Westerberg. The mercurial former lead singer for the mighty Replacements moved from glossy pop rock to over-produced singer-songwriter navelgazing to under-produced home recording reclusiveness, from major label “next big thing” to indie label “has been,” from sober to drinking again.

Westerberg’s cult status is consecrated, to an extent, by the Rhino collection, “BESTerberg: The Best of Paul Westerberg,” a curious 20 song collection culled from six of his nine albums, plus assorted extras, that feels like a condensed version of what should have been a three record set. B-sides and soundtrack contributions, like his anemic cover of “Nowhere Man” and the AIDS-themed rocker “Stain Yer Blood” (finally available without the “witty banter” from the tv show “Friends”) properly belong on a fuller collection of odds and sods (call it “RESTerberg”), along with some good stuff that didn’t make the cut, like his covers of “Make Your Own Kind of Music” and “Sunshine,” as well as the Danish bonus track, “33rd of July.” Ponderous clunkers like “A Star is Bored” and “Man Without Ties,” however, are more properly classified as “WORSTerberg.”

What’s good on here are mostly some mid-tempo ballads filled with regret and ennui, like “Things” and “Once Around the Weekend” (presented here in a too-busy alternate mix). The wistful “Love Untold” manages to overcome not only a slightly saccharine flavor, but makes a line about wearing clean underwear “just in case” sound charming and romantic. “It’s a Wonderful Lie” sounds like the sadly resigned flip side to the old Mats’ song, “Talent Show,” while “Lookin’ Out Forever” still sounds ragged and desperate, if a bit too much like Tom Petty.

Paul Westerberg stands now on the precipice of the peculiar variety of following his own muse that Alex Chilton rode to artistic oblivion. The next 15 years could be fascinating, or they could be a ridiculous train wreck.