Octopus is one of those foods that, in my experience, can be very good or mediocre. My first experience with octopus, as sushi (or Tako) was on the mediocre side of things. It was tough and rubbery and ended up as a plaything for the neighbor's cat... literally.
But as with many dishes, don't let a bad example spoil it for you. Since then I've had incredible preparations of octopus in both simple and complex dishes. My favorites by far have been very simple Italian preparations of octopus. When properly prepared, the octopus is simple, flavorful, and very tender. This is definitely a dish to try at a respectable restaurant. Freshness and preparation will determine whether it's enjoyable. And if you get a good example, it's ultimately not at all challenging. You will likely find yourself taking a bit to try it and then rushing back for a larger scoop before it's all gone.