Review I found on Amazon.com that I found good:
The first reason to get this disk is aesthetic. "Sweetnighter" is a unique recording: it includes the least structured, open-ended music that Weather Report recorded, and it was the last one they made before technological progress armed Joe Zawinul with more synthesizers than was perhaps healthy.
Some jazz fan acquaintances used to point to this recording and complain that Zawinul had kidnapped Wayne Shorter and was holding incommunicado in some safe house in Newark. To them there were no solos. They missed the point. Rather than soloing over an accompanying rhythm section, Shorter plays a kind of running commentary, coming in an out of a mix in which the bass(es) and percussion are given equal billing to Shorter's sax and Zawinul's keyboards. Sometimes everyone solos at once and it takes very, very accomplished musicians to pull this off without it degenerating into cacophony.
Yet it would be misleading to pigeonhole this record as Weather Report surrenders to the groove. Perhaps the most remarkable composition on the disk is Miroslav Vitous' ethereal "Will" which is percussion-less. Indeed, one of the remarkable things about this record are how varied the six pieces are: two open-ended jams - "Boogie Woogie Waltz" and "125th Street Congress;" a fairly conventional Shorter composition "Manolette;" two Zawinul tone poems a la "In A Silent Way" or "His Last Journey," "Adios" and "Non-Stop Home;" and Vitous' transcendent "Will."The other reason to get this disk is the way it sounds. The mass conversion of analogue tapes to digital formats has yielded some real disasters - e.g. Shorter's "Native Dancer" where entire instruments disappeared from the mix. This recording, in contrast, is a case in which the move to CD is a clear improvement over the original vinyl. Now the two basses on "Boogie Woogie Waltz" and "125th Street Congress" are clearly distinguishable, and similarly the multitudinous percussion instruments are more clearly defined. As another reviewer noted, never have Moroccan clay drums sounded so good. Roller toys and Israeli jar drums, either.
DISCOGS:
http://www.discogs.com/Weather-Report-Sweetnighter/release/481001