The hunk factor was immense. Jerry O'Connell is no stranger to beefcake shots; really, the only reason to rent his moves (Body Shots, Tomcats, Buying the Cow) is to fast-forward to the inevitable underwear scene. In Sliders his body was on display, often, but always when he was romancing a woman or being tortured by men.
Whatever the parallel world they zap into, men exist to befriend and then betray you; they always have an ulterior motive, they always are in league with the enemy. Women exist to be rescued, to offer alliances, and to fall in love with men.
And there were no gay characters, no gay themes, no nothing. Everyone in every parallel world was heterosexual. This is surprising, since John Rhys-Davies played gay characters elsewhere, and Jerry O'Connell is one of the most gay-friendly actors in Hollywood.
But maybe not surprising. Science fiction as a genre has been very resistant to gay characters. After thirty years and eight different series, there are no gay characters in any Star Trek franchise. None in Star Wars, Battlestar Galactica, Stargate -- well, actually, none anywhere. Producers continue to dream of gay-free new worlds.