South Beach may be slipping as a club hot spot, but it's not Opium's fault. The Asian-theme restaurant south of Fifth Street transmogrifies late at night into the raunchy, ostentatious epicenter of superficial glitz. Opium has emerged as the very best place for middle-age men to display their topless table-dancing (and often teenage) trophy chicks. Ergo the waitstaff at street-level Café Tabac, located directly below the joint, is inured to the unusual. "On Halloween," one waitress told us, "there was a woman who came down here in a completely transparent garbage bag, wearing no underwear and no bra. She pointed to a tear in her plastic bag and asked if we had a stapler." Suitably sutured, the reveler scurried upstairs, back into the still-breathing soul of South Beach.