I LOVE the Grand Californian, and think the hotel itself is as nice as a premium WDW hotel.
That being said, the concierge service does NOT measure-up. We stayed at the concierge at the Poly, and it was phenomenal. GC concierge just didn't have the selection; the beverages were not left out, so you have to ask for them (water & pop); they serve the wine, rather than self-pour; the room is small, so a couple of times we didn't have a seat in the morning or during wine & cheese (people were really nice about sharing tables!); there was no dessert/cordial time at GC.
I posted a trip report, including information about the Grand Californian concierge back in April. The title was something like: Day One: April 10-13: Grand Californian Concierge...