I get a feeling the non-amazed responses are from people who haven't finished the game yet. It takes a lot of time for the story to really build up steam.
The only flaws the game has are mere nuisances. Personally, I'd say the biggest flaw is the balance issue where if you do a lot of sidequests, you'll end up way overleveled for the main story, so if you want a challenge you have to make sure to only do the missable sidequests, which are marked as such. A difficulty setting would have fixed this completely.
Aside from minor quips like this the game in pretty much perfect though. There aren't many games that fit that description.