On balance, the merits of the San Francisco Ballet's new version of "The Sleeping Beauty" -- given its East Coast premiere at the Kennedy Center Opera House Friday night -- outweigh its drawbacks, and the production as a whole must be counted a success. It's visually resplendent, for the most part. And it demonstrates anew the much enhanced stature of the San Francisco company after a half decade of artistic stewardship under Helgi Tomasson. The troupe has the depth to meet handily the casting challenges of this most demanding of ballet classics. And Friday night's dancing boasted a level of style, technique and artistry that could conceivably be matched only by a few of the nation's other major ensembles.

Nevertheless, the triumph is mixed, and one that raises fundamental questions of approach. The production -- the company's first full-length "Beauty" since the mid-'40s, timed to coincide with the 100th anniversary of the ballet itself -- was conceived by Tomasson in concert with designer Jens-Jacob Worsaae, who transposed the setting from France to imperial Russia of the 17th and 18th centuries. The choreography is ascribed to "Tomasson after Marius Petipa"; it preserves the best-known Petipa landmarks, such as the "Rose Adagio" and the "Bluebird" duet, but involves as well a number of original Tomasson insertions and substitutions.

All the departures from tradition, in the choreography, decor, staging and even concept, seem unobjectionable. That's not to say, however, that they're desirable or advisable. The historical heritage of classical ballet is uniquely evanescent and fragile, compared with that of other performing arts such as drama or music. We have only a pathetically small handful of "classics" to begin with; when you've accounted for the three Tchaikovsky ballets, plus "La Sylphide," "Giselle" and "Coppelia," you're very close to the bottom of the list of works for which any substantial sources survive. And these few standards themselves have been subject to countless alterations over time. If, then, you're going to monkey with them, there had best be very compelling reasons -- revelatory innovation, insightful new interpretation or genuine rejuvenation of some sort. Otherwise, one would look especially to the world's foremost ensembles, including the San Francisco Ballet, to help conserve these masterworks with as little new aesthetic adulteration as possible.

By this measure, Tomasson's new "Beauty" isn't very convincing. Its novelties are less conspicuous and radical than those of his earlier "Swan Lake," but in ways they are just as wrongheaded. Tomasson and Worsaae have argued that the transposition from France to Russia was justified because of the strongly Russian character of the music, and as a means of visually emphasizing the 100-year historical gap before and after Aurora's curse-induced sleep. But what has "Beauty" essentially to do with geography, or the fashions of an era? It's not about Russia, or Tchaikovsky. First and foremost, it's a fairy tale, and a parable about the spiritual trials of a young girl growing to maturity. It's precisely these aspects that the new production fails to enhance.

The problem with the decor is not that it's Russian; it's that it so lacks fantasy, mystery or romance. Yes, there are fur hats and onion-domed buildings in the Prologue, which give way to periwigs and Gallicized 18th-century dress in the last two acts, but probably many in the audience, certainly those unfamiliar with the ballet, would scarcely be jarred by this change from more traditional productions. What's off-putting is its matter-of-factness of look, which would be fine if this were a period drama; Worsaae is an excellent draftsman, and it shows in such details as the scenes and figures depicted in the hanging tapestries of the Prologue. Nothing in the physical design of any of the acts, however, adequately conveys the sense of the marvelous or transcendental which should be "Beauty's" graphic crux.

So it is with Tomasson's choreographic emendations. Apart from the two quite fine solos for the Prince in Act 2, which flesh out the role effectively in ways lacking in the original, Tomasson's contributions -- including a folkish quartet for Aurora's suitors, a bland "Garland" Waltz, and innocuous Act 3 divertissements for Beauty and the Beast and Harlequin and Colombine -- don't wreak any havoc with "Beauty" but they don't do much good either.

Other facets of the staging also tended to inhibit enchantment: the obscure positioning of the infant Aurora in the Prologue, where she should be the focus of every eye; the perfunctory staging of the Prince's awakening kiss in the Vision Scene; the lack of a Panorama in the same scene; and the curtailing and neglect of the ballet's mime passages. There's also the matter of names. In this version, Carabosse becomes the Fairy of Darkness; Catalabutte is the Master of Ceremonies; and Gallison becomes the Prince's Attendant. Small matters, but a further depressant to one's yearning for the enchantment of fable in this context.

It did not help, Friday night, that Evelyn Cisneros's Aurora had no magic. She danced correctly and well, very well, especially in vigorous allegro passages, and she projected a reasonable amount of girlish freshness and ardor. But there's more to Aurora, and scarcely any of the lyric nuance that can take the role into celestial realms was to be seen. The orchestra's rendition of the Tchaikovsky music, under the baton of Denis de Coteau, also made little of its opportunities for romantic effusion.

At this point you may be wondering what was admirable and redeeming about the performance, but the fact is there was a very great deal, mostly coming from the dancers. To start with, there was the Prince of guest artist Bruce Sansom of England's Royal Ballet, who gave the part a generous measure of aristocratic grace, dramatic conviction and amorous fervor, and who evinced deep rapport with Cisneros. There was the "Bluebird" couple, Shannon Lilly and Andre Reyes (who's got technique to burn and eye-popping elevation), who gave as scintillating an account of this virtuoso challenge as any we've seen in many a season. There was Muriel Maffre's Lilac Fairy, rather mannered in her one dance solo, but otherwise a figure of sweet radiance and ethereality. And there were the extremely fine variations by the Fairies, especially those of Lilly, Julia Adam and Jennifer Karius; the ebullient dances of the Jewel Fairies and their cavaliers, and those of the Little Lilacs, the other divertissement numbers, and the Vision Scene nymphs. In other words, in the department that ultimately counts the most -- the dancing -- this "Sleeping Beauty" ascended to glory.