I've used my
DVC points to stay at the Grand four times now and plan to continue doing so! Despite the general opinion that using points outside of DVC villas is not good value, I truly think GC is an exception. The cash rates are outrageous and a points stay would include taxes and resorts fees. Just try to avoid a Friday or Saturday night stay.
If you're interested in using points for concierge, make plans as early as possible. I tried to book conciege for mid-June during mid-week and MS said concierge was not available for the three nights that I wanted. Same thing when I tried to book two nights mid-week for end of July. Since they don't use wait lists for DL hotels, I was encouraged to call back often and check if availability opens up. This did not surprise me as I had difficulty securing conciege for a February trip when I tried to book last November and only got one night out of four, which turned out to be a good arrangement as we concentrated on the parks and rides the first three days and were able to sit back and enjoy the hotel amenities and the food/drinks in Concierge Lounge the last 2 days. We requested to be in the same room as I did not want the hassle of checking out/ checking in because of the concierge privilege for the last night of our stay and the hotel accommodated our request.
Whether concierge is "worth it" is very subjective, but it's fun to do it at least once and doing it on points is much more affordable than paying $400 cash or more a night additional during peak periods!