It's been a couple of years since we did concierge level, but from what I can tell it hasn't changed. The last couple of years we've gone, we haven't purchased it. You will have a room with a "nicer" view - although the last time we went we had the same view without concierge level. There is a lounge that has breakfast items and wine and cheese in the evenings. We did find it handy to stop in for bottled waters before hitting the parks, or for a soda or something in the afternoon, and there is someone to help make reservations, although I've found that a lot of times it is easier to make the reservations on your own, as then there is no middle man trying to determine alternate times if needed.
Hope this helps!