You show your deck to 10 people, you get 10 different sets of feedback. Feedback is useful, but you have to make the call to whom to listen, and whom to ignore. People have different backgrounds. Experts, colleagues, and insiders give different feedback than your close family. Listen more carefully to feedback from people that resemble your target audience before putting all your fundamental charts in the appendix.
The more often you give a presentation, the more you start developing your own flow. When you reach a stage where you can deliver a pitch without going back and forth between slides, and are not getting audience questions you were about to answer 3 slides later, you probably got it right. Even if people walk up to you afterwards and suggest to collapse a few slides into one to reduce the slide count.
Art: Escaping Criticism by Pere Borrell del Caso, 1874