Too often in the sphere of dance it seems that youth is the be- all and end-all. Given that energy, that flexibility of spine, that willingness to be moulded into whatever awkward new shape a choreographer can devise, it's easy to see why some dancers are made to feel they're over the hill at 25. But for Jiri Kylian, the far-sighted director of Nederlands Dans Theater, youth is just the beginning, an apprenticeship to artistry.

NDT2 was set up as a training ground for the main company and is the more familiar to British audiences. NDT proper has not been to London in decades. No one's complained, for the under-25 squad is a fine working model of the Kylian ideal: immaculate schooling, dazzling technique, terrific verve. Yet its specially tailored repertoire lacks the challenge of NDT: the "Dans" is all there but "Theater" is not. We're still on the nursery slopes of life, in Kylian's book. The serious stuff is for the grown-ups.

NTD2 began its tour at London's Peacock Theatre on Thursday with a generously long programme, presumably designed to show off its range but which homed in on just two youthful preoccupations: love affairs and having fun, which pleased the predominantly young audience well enough. But a tendency to prettiness sapped the more serious moments. Kylian's Songs of a Wayfarer, set to Mahler's Song Cycle as a series of tender pas de deux, was first performed by older NDT dancers in 1982, but here the five duets came across as merely charming, occasionally poignant romantic encounters. When a boy holds his partner, coiled foetus-like above his head, we're meant to think of the child in the woman, but here it became clever acrobatics. The imagery of death - a woman's body lying on the flat of a man's outstretched forearms (phew!) suggested no weight of experience.

More convincing were the pieces made specifically for these young bodies, such as Hans van Manen's Solo - not really a solo at all, but a stream of virtuosity danced in competitive relay by three male soloists. A relentless cascade of Bach violin semi-quavers set the pace for a breathless sequence of prinking, prancing, scuttling steps that might have made lesser dancers look fey. But these are men who can put on white tights and a sawn-off T-shirt and know they still look great. Hans van Manen's featherlight humour makes the combo of well-developed biceps and twinkle toes seem the sexiest thing on earth.

Englishman Paul Lightfoot is a favoured Kylian protege, and though scarcely too old to qualify for NDT2 has already choreographed a lot for them. I don't know how they cope. The costumes for his Skew-Whiff posed the severest possible threat to masculine dignity in peculiar hi-top trunks in banana yellow, but still the dancers came out smiling. Bananas came to mind more than once in this oddly jocular piece, though the joke itself passed me by. Quite why the single girl was goofing and gurning and one of the boys pretending to stave off an urge to pee, I know not. Other people found it very funny.

Johan Inger's Sammanfall - the other piece by an NDT dancer - was more memorable, though still in the groove of young love on or off the rails. But it had an intriguing, Kafka-esque subtext, its mournful Gorecki score suggesting some old Iron Curtain repression with Big Brother as a large eye peering down from where the moon should be. Here all the NDT essentials came together: crisp and clear dancing, compelling choreography, and that smidgen of something other, that ability of dance to probe a subtle sphere of theatre in a way theatre itself is too concrete to attempt.

Our closest British equivalent to the ballet-based NDT2 style is Rambert, who are back on the road with their ever-changing triple bills, a formula that's become comfortable in the best possible sense. Beginning, middle, end. Something for everyone. But only when the balance of works is right. In Brighton last week to premiere Port For Angels, by Per Jonsson, Rambert made the rum decision to put with it something very like it.

Christopher Bruce's Stream (a lovely piece) covers too similar territory in a similar mood, to a much too similar electronic score. Deja-vu apart, the Jonsson piece was remarkable. Not for its steps, which may be news in Sweden but hardly push any boundaries here, but for the soft air of sensuality that pervaded every moment. Posses of black-clad marshal-looking "angels" slink, swarm and prowl towards changing sources of light. Lars Akerlund's soundscape hums quietly like the internal workings of the Starship Enterprise. But this wasn't the only music. We were made minutely and deliciously aware of the swish of satin thighs, the pad of leather slippers, and the hiss of human breath. The dance thing is not just a looking thing. It's the full works.

NDT2: Brighton Theatre Royal (01273 328488), Mon & Tues; His Majesty's Aberdeen (01224 641122), Fri & Sat; then touring. Rambert: Birmingham Rep (1021 236 4455), Wed-Sat; then touring.