4 out of 5 stars.
Good stuff:
Graphics are outstanding.
Exploration of the map is great. And its a very big map.
Lots to do, things to see, places to go.
Fight sceens are great. You get to be dumbledor at one point in the game.
Many hours of enjoyment.

Bad stuff:
User interface stinks. Couldn't adjust mouse properties.
Hard to get harry to run in a straight line. Keyboard control lacks fine tuning.
Sometimes its difficult to get a view of a particular area you are trying to see.
Ron and Hermione tagging along get in the way a lot of the time.

I got the game Friday, have it 96 percent completed on Monday.
Personally I found this one better than GOF.