Keep in mind there are many things to do at the Universal resort besides Harry Potter. The Jurassic Park area, Suess Landing and all the areas are all amazingly themed and just as awesome. So don't think of it as just going to see the Harry Potter world, that would be kind of like thinking you are going to DIsney just to do Pirates of the Caribbean, there are tons of amazing islands, attractions and rides to do. You can think of it a lot like Disney in the sense that it is a "theme" park, it is not just a roller coaster park with harry potter thrown in.
I would also advise you to search for the thread on this board that is titled "Universal / Islands of Adventure Pictures of the Day" or something like that. Many posters have posted tons of great pictures on that thread that will give you an idea of the amazing level of detail the Universal parks have to offer.