Aslam is a soft speakig guide with lots of knowledge to share and who does not hesitate to say "I don't know" when confronted to highly technical questions (e.g. "does the Taj Mahal follow the proportions of the gold number?"), which is for me a proof of honesty and professionnalism.
He is a native of Agra who knows and loves his town. The handicraft shops where he drove us provided us excellent technical presentations of their craft before going on to their usual selling techniques.
I recommend hiring Aslam if you are looking for history and culture.