We were there in May and purchased an upgrade. It was $50/night. I must admit though, I second guessed my decision to upgrade. We've stayed conceirge at Poly and absolutely loved it. I wasn't as satisfied with WL. My primary concern was that you had to ask for most beverages (canned soda, choc. milk, etc.) There were times the CM was very busy with another guest and we got tired of waiting and left. The CM's were very friendly and helpful. I always enjoyed grabbing a bottle of water before heading to the pool or the parks. You can't do that anymore. They have a large bottle that you pour into individual glasses. The offerings were nice but in comparison to Poly it just seemed like there was much less to choose from.
Truly, it is an "individual" thing. As I said, I absolutely loved Poly/conceirge. Stayed there twice. I wanted to experience it at WL (one of my fav resorts) and I'm not sure I'd do it again. I certainly would try concierge at other resorts at least once.