Maybe I was spoiled by living in a Greek neighbourhood growing up, but I found Penelope utterly forgettable. Literally. I can't remember feeling any particular way about the food, which I barely recall-- I had gotten some chicken dish? Not souvlaki? I suppose this isn't a very bad thing; I'd have remembered it if it was horrible. But sitting here now, I remember little more than 'this was sustenance.'
The decor and atmosphere are nice enough, and I'd imagine it an excellent choice if your relatives were in town or you're seeing a show nearby. It's not by far the best Greek I've ever had but-- from what little I remember-- not the worst.