We like it just fine. It's not what I would consider destination dining, but if you're staying at OKW, or want to take a boat from Downtown Disney, it's not a bad option at all. I really like the conch chowder, which is something you don't see anywhere else.
The main menu is pretty typical WDW resort fare - steak, chicken, fish, pasta. Olivia's does have a winsome laid-back island feel.
I'd consider it a no-fuss meal, if that's what you're looking for.