The Joffrey Ballet settled into the Kennedy Center Opera House Saturday night for a nine-day visit commemorating the troupe's 25th anniversary, but the launching was a curiously muted affair.

The reception from a virtually full house was cordial but subdued, particularly for an opening night. The company, full of verve as ever, deserved better, perhaps. But both the program and the performances tended to underscore the contradictions in the Joffrey's makeup, and the price the company pays for its image as America's whizz-bang junior wonder of classical ballet.

On one side, there's the democracy of its community of dancers, all treated as equals and called upon for an awesome diversity of challenges. On the other side is a bland anonymity--even after considerable exposure it's not easy to distinguish the individual performers from one another.

Similarly, there are the Joffrey dancers' justly celebrated speed, vim and youthful energy, which are certainly exhilarating but often dissolve into an affectless blur of pinball frenzy, like urban traffic. And then there's the once-over-lightly approach to style, engendered by the striving to make a broad swatch of repertory accessible to anyone. In its most populist vein, the Joffrey company has the effect of a cola drink--it picks you up, gives you a quick fix. But the lasting nutritive value is close to nil--the lift fades as quickly as the bubbles. There are, to be sure, other, far more substantial aspects to the Joffrey Ballet, as its splendid 25-year record makes clear; however, they were not on view Saturday night, except fleetingly.

Two of the ballets were by Gerald Arpino, the company's associate director and resident choreographer. Arpino encapsulates the troupe's ambivalence. He's a skilled, dependable craftsman who on occasion produces work of genuine imagination and flair. But mostly he churns out plastic ballets that are slick, flashy, frantic and shallow, and these two follow the formula.

"Suite Saint-Sae ns," with its schlocky score, is like a New Year's Eve noisemaker. It begins and ends with dancers zooming across the stage in crosswise jets, as if sprayed from pressurized spigots. In between comes an incessant, self-consciously tricky whoosh of steps, lifts and jumps--even the slower "Serenade" movement never stops for a breath. The company worked hard to make the dazzle seem real, but everything evaporated on the instant.

"Epode" may be the first carryout ballet. The ballerina--Patricia Miller, whose supple extensions and exaggerated stretch are neatly shown off in this vehicle--is literally carried out, held high aloft horizontally by four men. Before that, she's been tossed, flung up, spun and lifted in an orgy of male adoration, to the fittingly meretricious strains of the Shostakovich score. Arpino's choreography is not as busy as usual, but it is even more forgettable.

With Jiri Kylian's elegaic "Return to the Strange Land," dedicated to the memory of John Cranko, the choreography entered another plane. Kylian's rising and sinking spins, his great circular sweeps and transitory body linkages (like those of Pilobolus but for wholly different esthetic ends) give his work a distinctively personal, poignant stamp, and in this work, at least, enhance the dark pathos of his theme. Ruthanna Boris' humorously rollicking "Cakewalk," the Joffrey staple that concluded the program, was also a welcome item, but the dancing only sporadically matched the sparkle of past performances.