The original miniseries was very good, the sequel miniseries less so, and the weekly series was pretty bad, as I recall.
Yeah, the TV series was pretty cheesy, special effects left a lot to be desired. When they did show the Visitors’ reptilian nature, they looked like the Gorn from the original Star Trek.
Still, there were a few memorable segments — like the ep reminiscent of the ‘Les Marseilles’ scene from “Casablanca”, where patrons of the Resistance club sing God Bless America to drown out a Visitor playing the lizard’s anthem on the piano...