Yeah definitely complain about his demeanor, even if you don't mention his...er, job skills. If THAT many people have taken note of the way he treats customers, it means that he's probably scaring business away. Managers tend to notice things like that. With any luck, they'll get him to be at least "less creepy".
“Always remember: you’re braver than you believe, stronger than you seem, and smarter than you think” - Christopher Robin