If, like me, you are a history nut with a particular interest in totalitarianism and architecture, this will be right up your strasse.
The statues look incredible; there's something very humbling about standing next to a man-made creation that utterly dwarfs you, which was of course the whole point of the original exercise.
As others have said make sure that you pay extra for the tour - the guides are excellent and explain the the story and historical context behind each statue. Without the tour I can see why people may not take much out of here beyond 'creepy stuff in a park'.
Memento Park is a fair journey out from the centre of town - about an hour or so by bus through suburbs and countryside - so make sure you leave enough time if you've got a plane to catch or other pressing commitments.
If you own or manage Memento Park, register now for free tools to enhance your listing, attract new reviews, and respond to reviewers.