They've reconstructed the space in front of Philadelphia's palatial City Hall, furnished it with a cafe, a high-tech spray fountain and movable chairs, and rebranded it Dilworth Park. But the vast granite prairie is still very much a plaza, with all the weaknesses the word implies.

There is no doubt that this important civic space, once a smelly, run-down municipal embarrassment in the heart of Philadelphia, has been greatly improved by the Center City District's Paul Levy, who marshaled a dream team of Philadelphia's most renowned designers and engineers. The amenities, from the food vendor to the picnic lawn, are reason enough to applaud.

Yet Dilworth's new comforts, which won't be complete until November, are undermined by an uptight and controlling sensibility. Under Levy's leadership, the new design was intended to be the polar opposite of the 37-year-old plaza, a hardscape extravaganza by the late Vincent Kling, the same midcentury modernist who exhausted a couple of quarries building LOVE Park, the Centre Square towers, and Municipal Services Building and its plaza.

In place of Kling's tricky level changes, gratuitous barriers, shadowy hiding places and puffed-up monumentality, we now have a flat, multipurpose surface, wide-open views - and a new kind of puffed-up monumentality. There are vast amounts of hardscape.

The layout is intentionally easy to navigate. Olin, a nationally known landscape architecture firm, split the space in half, embedding a large, flat, rectangular fountain on the north side and a green lawn and smaller fountain on the south.

A pair of swooping glass ski jumps announce the entrance on 15th Street, like modern castle gatehouses. Designed by KieranTimberlake, these glass canopies house the stairs leading to the underground transit corridor, which has been reconfigured. The advantage of having everything transparent and low is that you get great views of John McArthur's regal Beaux-Arts City Hall facade, with its sculptures by Alexander Milne Calder.

For Levy and the Center City District - a group funded by downtown business and real estate interests - the Dilworth reconstruction marks the capstone of a decadelong crusade to clean up the public spaces along the Parkway. The best, Sister Cities Park, is an enchanting wonderland that has become a hugely popular hangout for the young families that are repopulating Philadelphia's rowhouse neighborhoods.

At Dilworth, Levy sought to apply his considerable organizational and fund-raising skills to a larger, more high-profile canvas. The 2.75-acre site is not just the place where the Parkway begins; it is the site of William Penn's original Centre Square. Of all downtown's public spaces, it is the one with the greatest claim to being Philadelphia's communal family room. Dilworth also sits atop a nexus of transit lines, making it a gateway of sorts to destinations like the sports complex and Convention Center.

Although replacing the plaza was Levy's real aim, he was able to raise a substantial part of the $55 million budget by pitching the redesign as a transit project. During the construction, overseen by CVM and Urban Engineers, elevators were installed to provide much-needed handicap access to the Market-Frankford platforms and trolleys (though not to the Broad Street subway), thus helping SEPTA meet federal requirements.

In return, Levy was given a free hand to make Dilworth anew. He envisioned a welcoming oasis that would replicate Sister Cities' playful spirit while also providing City Hall with the dignified forecourt it deserves.

But the inherent tension in those goals is vividly on display. The aesthetic is all wrong for a city eager to remake itself for an expanding creative class.

Yes, there is real magic when the fountain's jets of water shoot into action, but inactivated, the granite landscape is dry and stiff. The new Dilworth is a suit in a jeans-and-T-shirt world.

It sounds strange, but the designers' emphasis on perfection is suffocating. They bludgeon you with "high quality" materials that evoke the atmosphere of a slick corporate lobby. Five types of granite are used, ranging from speckled white to dark black, on the plaza surface.

Olin's sculpted benches, which are seductive and beautiful forms, also are granite. A wooden version, similar to Olin's design for nearby Lenfest Plaza, would have softened the official feel of the place. So would some additional shade, but all the greenery has been relegated to the periphery. The nicest spot is a small grove where the chairs have been arranged on crushed gravel rather than granite.

Maybe I spent too much time in beer gardens this summer, but I found myself longing for some of their laid-back, serendipitous vibe. I'm not suggesting that the industrial bric-a-brac style perfected by designer David Fierabend is right for Dilworth, which has the burden of serving as the city's civic stage. But surely there are ways to make the plaza feel less like the playground of the plutocrats. My sense is that even the completion of the lawn later this year is unlikely to dramatically change the overall atmosphere.

There is now plenty to do at Dilworth, yet you are frequently reminded of what you can't do. Take the heavy-handed way the CCD communicates its ban on skateboarding. Since the ski-jump canopies are an irresistible attraction to skaters, signs have been bolted to the railing warning: "This is an entrance for transit, not to the emergency room. NO SKATEBOARDING ALLOWED."

As architectural forms, the glass canopies look gorgeous from afar, as weightless as soap bubbles. But up close, the reality of their construction sets in. The layers of the five-ply glass are clearly visible and the fantasy of pure transparency is further eroded by the metal fence that protects them.

The canopies may also be acting like a giant magnifying glass. On opening day last week, when temperatures soared, I found the stainless steel handrails almost too hot to touch.

The main advantage of the design is that the surface can easily be converted to seating for a concert or a winter skating rink. In theory, it can also be the staging group for civic protests.

But, according to Levy, the city will issue permits for such gatherings only if there are no competing activities in the plaza. Will a few sprays of water be used as a rationale for keeping protesters out? After all, the old Dilworth was the site of the 2011 Occupy protest.

In granting the CCD a 20-year lease on Dilworth, the city has effectively privatized the plaza. In exchange, the CCD will provide white-glove maintenance and organized fun. We might not feel entirely comfortable in this new Dilworth "park," but we can be assured that it will always look perfect.