which model writes like a human for client emails, is sonnet 5 the one

i run a 4 person shop and send maybe 20 client emails a day, so the voice actually matters. been on gpt and everyone here is right that it reads like a linkedin post, every paragraph ends in a little bow. i saw sonnet 5 became the default june 30 and people keep calling it the best writing model. is that a real difference or forum hype? want to know before i move my whole workflow over