Morton's is the Loehmann's of the dining world. You buy a certain luxury and quality but in a setting that is about as relaxing as Metro Center at rush hour.

You pay for this luxury. Not in an outlandish amount of money; though the steaks are about $20, accompaniments are reasonably priced. You pay in terms of waiting for a table after 7 p.m., and in risking a noisy meal of headache level, and in possibly misordering (the lobster is unfortunately baked instead of steamed, and the chicken can be dry and dull, while the thick veal chop is a safe bet). And if you arrive after about 7:30, by the time you are seated the kitchen might be out of roast beef.

Once you have wangled a table, though, you are in good hands, and you're in for a good meal if what you have in mind is steak. The steaks -- particularly the porterhouse and especially ordered black-and-blue -- are knockouts. The meat is aged to full flavor and utter tenderness, cut thick and charred to a crusty surface that seals in the juices. And the accompaniments are generally just as dazzlingly simple: luxuriant smoked salmon to start, caesar salad with plenty of tang to it, hash browns that are as crunchy as potato chips, sauteed spinach and mushrooms, baked potatoes that could feed half of Idaho. And even the souffl,es for dessert are lighter than air.

At Morton's you can spend extravagantly and eat extravagantly, but you have to put up with enough guff that you needn't feel decadent. 3251 Prospect St. NW. 342- 6258. D $13-$30. D daily. Closed Sun. AE, DC, MC, V. No res after 7 p.m. Full bar.