A great episode that holds up beautifully. True, "Tourist Attraction" was a cheesy, poor episode. I'm not a big fan of "Behold Eck!" either. But even "The Human Factor" played better than I remembered. And it's fun to note that Joseph Stefano lobbied for Sally Kellerman, and that role got her an agent and more work, and eventually tailored an episode for her in "The Bellero Shield" (another great episode). He was her "Alfred Hitchcock" according to Schow book excerpt on the show.
My The Invaders DVD took 19 days from Deep Discount, but the show holds up well (except for the ghastly orange faces in the first few episodes). And you will no doubt be identifying much more TOL cues when you hear that "Beachhead" pilot. They're all over the place.