It's hard to say. Maybe after a couple of dates you'll be able to have a better feel for it? With only phone calls and virtual communication, it's easier to let your mind paint a picture. Maybe you won't gel afterall but spending time together matters imo. Body language and facial expressions can enhance or dimmish expressive communication. Maybe he is a dud for you but I don't know if I'd personally write someone off over a few phone conversations?