I ordered one of their DVC Member packages when we had our first DVC stay. It was executed well, it was exactly as described (they even let me substitute some things). I had given them a timeframe of a few hours and I just kept everyone away at dinner and when we came back - viola! A door sign, lots of snacks, footprints, a blanket, a signed picture, etc. Even my husband was surprised, it was an awesome treat.
It was pretty expensive, so not something I'll do every visit... but it sure was fun! And we kept some of the little items and I'll try to do something like it myself on our next visit (we had Mickey footprints, a note about cookies from Minnie, etc). My daughter loves the blanket and the backpack stores all our Disney stuff between trips.
One thing that surprised me - they won't have it in your room ready upon check-in, although they will do it later that evening.