Does having an adult circumcision leave you with a worse scar than a child circumcision?

Can only speculate: The procedure itself is much more involved: general anesthesia, sutures, swelling, itching, recovery etc in the adult. Add the anticipation & remembrance of the process in an adult. The mental residual is quite different than the infant who, when i ask kids, never remembers that anything was done.The physical scar is similar & a reflection of the skill of the surgeon.

No: Though you will be aware of the scar from the time you take the bandages off. The penis will look different and unfamiliar. It may not look like the 'penis' you imagined. The scar can be visible for 12-18 months. At the end of the day the scar is unlikely to be an issue.

Not if done well: A neat sleeve resection circumcision in an adult should heal with minimal scarring, just take longer to heal. A "hack-job" circumcision may well leave an unpleasant scar.