I think it's an ok episode, but I don't think the Miles character is conniving and evil enough. She's just sort of being led around by circumstances, rather than executing a diabolical master plan, like the really evil Columbo villians that you love to hate.
I like it too ... the only aspects of this episode that keep it at the bottom of my list are the polyester fashions, the unflattering wig on Vera Miles' head, and of course, Sian Allen.
Like the "lovely touches." The fake beauty mark, the pants suits, giving her security guard the peck on the cheek, and that shocking pink board room. Yow!