Saying L was in advantage over Light Yagami is preposterous imo. Light had the Notebook and knowledge of all its rules, unlike Ryuzaki who only gained knowledge of it after Higuchi's death. Light Yagami also had the help of a fricking Shinigami (Rem), who wanted at all costs to save Misa's life and even bribed Ryuk to wrote fake rules in the Death Note that'd presumably end all suspicions they had against Misa and Light, which only happened with the dickheads, idiots of the team investigation, but didn't really happen with L, who still was able to surprise Light with his questions and deductions and aggravated Rem's obligation to kill L, otherwise they'd not be totally saved.
It's clear to me Light had the advantage.