Slade is like Batman, it's all about the prep. He wouldn't face Spiderman directly unless it was unavoidable, and even then it would be mostly defensive. Given a week, if he knew who Spiderman was (Getting the contract from Fisk, that's a safe bet) he'd go after Peter's family and friends, set bombs across the city, and do everything he can to wear Peter down mentally and physically as much as possible before going in for the kill.