Two development teams are playing a high-stakes game, vying for the $1.1 billion contract to renovate and redevelop Miami Beach’s convention center and its environs on 52 pivotal acres in the heart of Miami Beach. Both teams include legendary architects and renowned landscape designers and plans with an extraordinary level of intelligence and promise.

The Dutch architect Rem Koolhaas and his firm OMA paint the picture with a big brush and focus on those all-important links to the rest of the city. The Danish architect Bjarke Ingels and his firm BIG draw inspiration from the architectural rhythms of Miami Beach, looking closely at the vital edges and the way they relate to and even help create the adjacent neighborhoods.

Both proposals show a powerful and striking architectural vision of an urban complex the likes of which we have not seen in South Florida, or for that matter, in America: sleek, smart, sophisticated, faintly futuristic and handsome. Whichever project is picked, the key will be to hold the design to that high level.

Bounded by Washington Avenue, 17th Street, Meridian Avenue and Dade Boulevard, the site is home to the city’s convention center and much more: Miami Beach’s prized botanical garden, the historic Carl Fisher Clubhouse, the Jackie Gleason Theatre, City Hall, plus acres and acres of parking both in surface lots and in the ugly-ignominious 17th Street Parking Garage.

The mandate is no small one: reinvent the convention center (without tearing it down), add a hotel, ballrooms, parking, parks and gardens, cultural facilities, offices, shops, restaurants and rental housing while honoring, restoring, repairing or replacing what is there.

To say that both architects are brilliant and visionary is to beg the point. . Both bring to the table European-bred visions of urbanism, ideas bred in a culture where for centuries cities have incorporated big buildings —palaces, museums and other centers of culture—as part of urban life without letting them wallow in a sea of asphalt parking, American style.

South Beach ACE calls upon the work of Koolhaas’ OMA, which has offices in Rotterdam, New York, Beijing and Hong Kong. The landscape team is the much-honored firm of Michael Van Valkenburgh Associates of Brooklyn and Cambridge, along with Miami-based Raymond Jungles. Though its national development partner is Tishman Realty, locally the project is led by developer Robert Wennett, best known for his venturesome 1111 Lincoln Road parking garage.

Portman CMC, led by the Atlanta-based Portman Holdings and John Portman & Associates, features the rising-star architect Ingels, whose firm has offices in Copenhagen and New York, and the Dutch landscape design firm of West 8, designer of quite magical SoundScape Park in front of the New World Symphony’s building. The team’s local contingent includes the owners of the Bal Harbour Shops and developer Ugo Colombo.

But the two plans reflect strikingly different visions.

New geometry

For Koolhaas, the primary driving idea was to reduce the footprint on the ground and create strong connections to Lincoln Road and the neighborhoods to the east. “The very key is that we interpreted the convention center in its north-south orientation as an obstacle to redevelopment that separates the city and the beach conditions,’’ Koolhaas says. “By orienting it east and west we create greater permeability. That is the real achievement.”