Well I've got to say I really enjoyed it despite all the unanswered questions, sometimes you just have to let the finer points go and enjoy the bigger picture. The fact they glued so many small details together sometimes seasons apart showed the attention to detail this show had. There were many many little clues and almost unnoticable things which added depth to the story without being absolutely critical to noticing them - it became a teasure hunt to spot as many as you could and piece your own theories together.
Lost was a roller coaster ride full of mystery and tackled some really big questions. It was never going to be able to satisfy everyone - because people wanted answers that were impossible to give and against the whole ethos of the show. A large part of the fun was building your own theories. However in the end the major plot lines gave enough detail for you to understand the basic concept of the show. One I thought was very moving and profound and nicely summised by that Lostepida quote.
I think the show made you consider your own values through looking at the actions and consequences of the characters in the show, and in essense was a lesson in morality and how to try and live your life. Locke's forgiving Ben at the end was a great example of this. A spiritual and moral guidance without referring to any specific religious group or notion of god.
Quite intelligently done I thought.
While the overall style of the show was sometimes a little cheesey, there's no denying it was a very intelligent and well thought out plot, and extremely addictive to watch.
Edit: I'd also like to add that I still think the opening scene to Season 2 was one of the most fantastic pieces of television I've ever watched. Absolutely genious moment.