But there were some significant differences.
Erik is best known as Officer Ponch on Chips (1977-83), a role which allowed him to consort with beach-babes and big-brother troubled teens (such as Leif Garrett), while never establishing any significant homoromantic bond with his partner, Jon (Larry Wilcox). Mario's characters frequently enjoy homoerotic buddy-bonds.
Perhaps due to the popularity of Chips, Erik was heavily identified as a police officer. He played parodies of his character several types, he actually was a reserve police officer in Muncie, Indiana, and he lent his name to several police-related organizations. Mario seems to have a wider range of roles to choose from.
And the most important difference: Mario Lopez has played gay characters several times and is a strong gay ally. Erik Estrada has never played a gay character and has never made a public statement supporting gay people. To be fair, he hasn't said anything homophobic, either.
In 2012, a photo of his Ponch character was found on a supervisor's desk at the notoriously homophobic Atlanta Police Department, marked with an anti-gay slur. It was unclear whether Ponch was "accusing" the supervisor of being gay, or the supervisor was "accusing" Ponch.
Either way, Erik Estrada had no comment.