with no air of the formidable conductor about him 这是with复合结构,about him并不多余,为with复合结构中的宾补,说明air的位置。about=around.
One of the reasons why the appointment came as such a surprise, however, is that Gilbert is comparatively little known. Even Tommasini, who had advocated Gilbert’s appointment in the Times, calls him “an unpretentious musician with no air of the formidable conductor about him.” As a description of the next music director of an orchestra that has hitherto been led by musicians like Gustav Mahler and Pierre Boulez, that seems likely to have struck at least some Times readers as faint praise.
为什么这里要加about him呢?感觉好像多余的成分!