By Paul Reidinger

FOR LOCALS, the hotel restaurant is terra indifferentia. Although hotels and restaurants trace their ancestry to a common forebear – the inn – the hotel restaurant in our day tends to be full of (or if not full of, at least slightly occupied by) ... hotel guests. Which is to say, either tourists or conventioneers. The main run of hotel restaurants, accordingly, tends to emphasize convenience, charges a pretty penny for it, and serves food that combines familiar American standards with watered-down versions of local dishes – cioppino, say, served in a hollowed-out round of sourdough bread. A local would be as likely to order such a preparation as to buy a postcard with a photograph of a cable car from a knickknack shop on Grant Street.

Yet it is one of San Francisco's more delightful paradoxes that some of our best restaurants are in hotels – are, in fact, more famous, if not more highly regarded, than the hotels that hold them. Postrio, Masa's, and Farallon are three such spots; when you are swept up in their powerful atmospherics and eating their singular food, you forget (if you ever knew) that you are somewhere in a hotel in which out-of-towners lurk.

It was to this pantheon that XYZ aspired when it opened in the brand-new, dot-com-friendly W Hotel four years ago. At the time its Moscone Center neighborhood seemed to be the core of the new San Francisco and its new wealth; nearby had risen Metreon, the Yerba Buena Gardens project, and the new modern-art museum. And behind the stove at XYZ stood Alison Richman, a protégée of Traci des Jardins with a similarly luxurious sense of freshened American cooking. Fair stood the wind for culinary glory.

But as we all have been told ad nauseam, the wind shifted, the economic sky clouded over, and so forth. Unlike Montage, Dine, and Mercury (to name three prominent casualties of the business-climate change), XYZ is still there, as is the W. And if you take a walk through the lobby to the restaurant's entrance, you might still think it's 1999, for clumps of youngish, black-turtlenecked types still linger, yipping forcefully into their cell phones (which they seem to hold and caress as if they were cats) about deals and prospects and similarly antique topics. The anachronistic effect is not unlike that of walking into a London men's club and feeling that one has literally stepped into an episode of The Forsyte Saga.

Is their presence the sign of a resurgence, or merely a shadow? I am inclined to suspect the latter. But what is remarkable about XYZ's saga is that, despite the tattering of its yuppie clientele and the turnover in the kitchen (the newly installed chief is Malachi Harland, a protégé of Paul Bertolli, onetime Chez Panisse chef and now proprietor of Oliveto), the restaurant is still powerfully good. Harland's food is in a sense too strikingly zesty for the generically cool surroundings in which it's served; with tall burgundy-colored curtains, plenty of dark cherry-wood trim, marble-topped tables, and spot lighting (all reminiscent, one way or another, of Mecca and Asia de Cuba), XYZ has the feel of rarefied soullessness and beautiful inhospitability one often associates with our down-and-out-in-Silicon-Valley types.

The humans who work in this chiseled environment are, thankfully, hospitable, though they push bottled water a bit too urgently for my taste. They know their stuff and provide useful recommendations – steering us to Harland's excellent hominy cakes ($8), for instance, a pair of disklike fritters, sweetly gold with a blood red ancho chili sauce and dabs of pico de gallo and crème fraîche. The kitchen's ethnic influences are muted, but at lunch a plate of pad thai (a bit pricey at $15) was – with its ribbon noodles, plentitude of peanuts and chunks of chicken breast, and vinegar-citrus sauce – better than what you would find at the vast majority of Thai restaurants.

Most of the dishes are AmeriCal, relying for their effect on good ingredients sparingly handled rather than on conspicuous kitchen wizardry. A soup of roasted eggplant and potatoes ($7), puréed to smoky smoothness, took its kick from a bit of cayenne pepper. A bouillabaise-like stew of cod and lobster ($27), in whose simple fumet bobbed marble potatoes and littleneck clams, was mostly about the lobster. And a hanger steak ($18), nicely sliced as if for a stir-fry and grilled to a voluptuous medium-rare as we'd asked, needed nothing more than a stack of perfect frites (not too thick, not too thin, not too crisp, not too tender) and a small pot of salsa verde to leave its devourer deeply satisfied.