Answering this question on Quora: “How do Arabs feel, speaking MSA/Fus7a with foreigners?”
If you are used to speaking MSA/Fus7a on a regular basis, that is, if you are a journalist or a teacher of MSA/Fus7a, for example, you probably feel OK. Otherwise, it can feel very tedious to maintain a conversation in MSA/Fus7a.
Link to the Quora thread: https://qr.ae/pK172b