“As architect Santiago Calatrava’s plan for the Chicago Spire heads to likely approval at the City Council’s zoning committee Thursday, readers are sharing their thoughts, questions and criticisms about the twisting, 150-story condominium tower, which would be the nation’s tallest building. Several readers pejoratively liken the supertall tower to a part of the male anatomy. Others, usually more positive about the design, favor the metaphor of a drill bit or a screw. Still others are asking fresh questions about the proposed skyscraper.”