Parts of it are nice. But that kinda sums up the problem with IOA. To me, it is as though it was designed to have all of the elements of what the designers considered a "great Disney park". Unfortunately, nothing ties it together, they are abstract lands that don't fit, or have any real place or back story. The place is very small and crowded (not with guests, but with carts selling cheap junk, tight walkways), and all of it's sightlines are destroyed by huge steel coasters. They really looked hard at Disney, and thought they could take replicate it's success. What they don't seem to realise, is that people have a heart string atatchment to Disney that runs much deeper than a collection of rides. The deeper attachment just isn't there at IOA, and it comes across as as series of almost random rides positioned around a very small lagoon. They tried to make the ideal park, but that's all it is, their "idea" of what a perfect park is, and it fell short.
You really should go, at least to check it out and to gauge it for yourself.