I've not heard of an offsite resort with a great shuttle service. If you hear of one, please let me know. The one at our hotel was expensive and only ran 4 times a day. We just ended up renting a car. I've heard the same about other offsite resorts.
I have never found one that I would rate any higher than adequate. Most only run hourly, early or late arrivals or pick ups are hit or miss and several only take you to the TTC and require you to take Disney transportation from there.