Our city, splendid and powerful as it may be, is certainly not very sexy. While DC is infused with a vibrance and energy that other cities may lack, the sights, smells and sounds of a newly opened Pottery Barn, sprung forth from the rubble of a block of Southeast row houses do not provide quite the same sensory scintillation as, say, a South Beach mambo, or a West Village table for two. Capitol Hill sexploits,…