Alhambra for Rome, Rome for Alhambra. Thrifty-minded colleagues discover the ups and downs of trading spaces. Would they do it again? Read on. Editor's note: In November, Times staff writer Susan Spano and Times website producer Jason La exchanged dwelling places. La, a twentysomething, got to nest in Spano's apartment overlooking the Forum in Rome, and Spano, who's not a twentysomething, ...