It's not often you see so many people don copious amounts of hair mousse and cool fashions before heading to a restaurant that specializes in hot dogs and funnel cakes.

But there they were one recent night, reposing in well-coiffed posses on the chic chocolate velvet furniture of 707 Restaurant & Bar, nibbling petite hot dog trios and deep-fried deli sandwiches with their tousled faux-hawks spiking skyward. One natty gent, a local TV pundit, toured the room in a pinstriped suit greeting friends. Another fellow in sunglasses glad-handed the passing crowds from his banquette like a boy-band idol, flanked on both sides by leggy girls.

Yes, there is style galore at 707, which is one of the most handsome restaurants to open this year. But are the scenesters being fed with substance?

That depends, of course, upon what you order from the extensive and affordable menu of updated American classics, which hits highlights with overloaded salads and a nearly perfect omelet. But on the whole, the cleverly fussed-with comfort food - something of a cross between Jones and Marathon Grill - is packed with more "whimsy" than "yummy."

Whimsy goes a long way in a space like this, which owner Ryan Margolis and his designer, Freeman Interiors, have crafted from an old dollar store into an appealing multivibe venue that reflects the versatile moods of today's diners. Outside, a breezy sidewalk cafe set beneath a swooping metal awning segues inside to a big square central bar and lounge, which in turn leads to the cushy formal dining room in the rear anchored by plush round corner booths, drum-shaped chandeliers, and minimalist decor.

The big square bar is reminiscent, in a sleek kind of way, of Fork's lively front bar, which has always anchored that pioneering bistro of Old City style with a genuine spark of neighborhood conviviality. And 707 has the potential to draw that same kind of energy for Washington Square, with reasonable menu prices (virtually everything is under $20), a smartly eclectic wine list, and enough pear vodka-spiked lemonade to keep everyone jolly.

Certainly the well-trained staff is in a good mood, though their tableside delivery is so dramatic they could be auditioning for the Walnut Street Theatre nearby. Our first waiter caressed every syllable of his menu descriptions with such mellifluous cooing, it sounded like phone sex for foodies. In recounting the elaborate seasonings visited upon the burger, he had me at the "dehydrated onions."

Had that burger been even half as tasty as the description, I'd be whistling a happier tune. But it wasn't: The 10-ounce patty was too finely ground, so overworked and tightly packed, that it had the texture of pate. And too many other dishes seemed to be the beneficiaries of more concept than careful cooking.

The kitchen often starts with good ingredients, like the excellent natural skin-on franks made by Rieker's in the Northeast with veal and bull meat. But the taste of that great dog is completely lost when sliced into three (a truly "petite" trio for $10) and buried in puffy buns beneath a mop of kraut, a glob of ordinary chili, and a streak of brown mustard. When exploring 707's hot dog oeuvre, the more straightforward pigs in a blanket, updated with a buttery jacket of puff pastry, are a better bet.

The signature Reuben spring rolls were one of 707's tastier comfort-food remakes, wrapping warm pastrami, corned beef, kraut and Swiss inside the crunch of spring-roll wrappers. And yet, those crisped cigars were so dainty, with their side of Russian dressing dip, that they lacked the zaftig spirit of the deli classic, available in its overflowing rye-bread glory just next door at Kibbitz in the City.

The menu has a few memorable items. The all-day omelet may be one of the best in the city, a fluffy blanket of eggs flecked with chive and rolled like a duvet around molten Swiss cheese and ham. The entree salads are appealing meals in a bowl, their heaping greenery laden with beautifully seared slices of hanger steak, provolone and crispy onions; or Cobb style, with grilled chicken and creamy dabs of Fourme d'Ambert bleu cheese.

Among the entrees, the meaty crabcakes, a blend of lump and claw, were perfectly respectable. A juicy slice of grilled mahimahi came over a helping of summery orzo salad. The grilled meat loaf was a good, if unremarkable, rendition of the diner standard, but the unbelievably crisp potato skins alone made it well worth ordering the dish.

I also appreciated the lightness of 707's microscopically thin-crusted pizzas, though I'd recommend going for the chef's more interesting daily inspirations. Our special pizza was topped with zesty smoked mozzarella, garlic, and ham. The menu's plain margherita was so underflavored, though, that its topping of chunked tomatoes was just boring (simple shouldn't mean "unseasoned").

Likewise, a special gazpacho was so haphazardly cooked, it was like eating a bowl of soupy salsa - though I appreciated the generous fistful of crabmeat mounded in the center. The honeyed chicken wings were another good dish that faltered on hasty technique; the plump wing meat had a chewy, undercooked spring that would have benefited from more gentle cooking. The big pork chop was impressively thick, but a little dry, despite its tasty pineapple salsa.

Desserts attempt the same updated comfort shtick, with equally mixed results. The chocolate layer cake is decent, but the thin icing lacks intensity. The toasted pound cake is too dry to come without sauce. This kitchen even muffed a seemingly unbotchable banana split, gracing our scoops of ice cream with little more than a dried-out brown banana, a few crushed nuts, and one lonely squeeze-bottle streak of chocolate.

But then arrived a funnel cake so marvelously fresh, its crisp lacery of deep-fried batter as big as a snowshoe, that I had to smile. Such a spark of whimsy is more than just a cutesy culinary wink when it's done so well. It gets devoured down to the last hot, crispy crumb.