With in person option the passport takes 10 business days to be issued (normally processing time), while in mail it takes 25 business days. I am OK with 10 business days. But the important thing I wouldn't need to send my original citizenship certificate with my application, and provide signed copies of IDs. I would also pay on the spot. Many advantages over the mail. This requirement was added just with the spread of Omicron at the beginning of Jan. Before that it was not required, but you had to wait 2-3 weeks for your appointment date, or walk-in and wait 3-4 hours or something