This is probably not what you want to hear, but in my opinion the identify takes so long because of the large geometry it's sending. To speed it up, either simplify the geometry or do not return the shape from the identify query. If neither of those are an option, perhaps somebody more clever than I can help. This, for example, should be MUCH faster (because of the "returnGeometry=false" parameter): http://maps.tucsonaz.gov/ArcGIS/rest/services/dsdMap_Engineering/MapServer/20/query?text=&geometry=&geometryType=esriGeometryEnvelope&inSR=&spatialRel=esriSpatialRelIntersects&where=OBJECTID+%3D+948&returnGeometry=false&outSR=&outFields=&f=json
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