First off I love this thread!
For us really it's a combination of being immersed in Disney, the convenience and the relaxation factor.
When I go in vacation it usually takes me a good week to really get relaxed to enjoy what I'm doing and not to think of work and other worries. That's pretty bad. However when you go to Disney and stay on site all that goes away quickly. Right away I know that most/all things are taken care of for me. That statement there just relaxes me. I know when I get on the plane on day one I can have just a big sigh of relief. I appreciate it and so do my wife and kids. That's what a vacation is for.. to relax and have fun, right?
So being on site there's no figuring out transportation from the airport, no renting a car, figuring out where to eat (or wasting money on crummy places to eat), driving to and from the parks and fighting the traffic, feeling that I wish we had of just stayed on site.
It's weird but being on-site gives you this sense of a special community that you're a part of. Again a feeling you cant describe. Knowing that you dont have to go home to a hotel that is far away and is accessed by your car and your driving at the end of a great day is a wonderful feeling.
Our first trip we stayed at the Embassy Suites Lake Buena Vista just off the east gates International Drive. It was a nice place to stay no question. The rooms were big with a kitchenette and they offered free breakfast. However we felt outside. Walking around our hotel was just not good enough entertainment being that close to Disney. During that trip we were at MK one day and stopped at the CR for lunch. My DW said wouldn't it be awesome to just stay here and not go back to the other hotel?? I looked around and said wow you are so right. This WOULD be awesome. So we switched to the CR for the next 4 nights. WHAT a difference it made. It was SO convenient, so relaxing, so cool! The ability to wake up, walk from your room and 2 minutes later your riding on the monorail to the MK or Epcot. Priceless. This trip was kid free as we didn't have any yet and even still it was a tonne of fun.
Our next trip in 2003 was incredible. We were totally immersed in Disney for 12 days with our 3.5 year old DS. We stayed at the Swan this time. The location was fantastic right beside Epcot and the Boardwalk. There were SO many things to do and see without even going to a park. Yes, without going to a park. Talk about immersed. I dont even think we gave staying off site a second thought. We knew wed be on site.
I remember one night walking leisurely from the Beach Club to Epcot with my DW and DS after eating at Beaches and Cream (in the BC) on a warm summer night. We took our time looking around enjoying the view of the Boardwalk, the resorts, the boats, the sand and the water. Everyone we saw had a smile on their face, holding doors for other people and just generally being in a great mood like us. It was something you can't describe but you felt... magic. And, also something you'd never get being off-site. Its like when you come out of a really really good movie, you know, and everyone is in that same great mood.
Every night we watched the Epcot fireworks from our room or the beach and we truly enjoyed the entertainment and action of what was going in. This post doesnt even come close to highlighting all the details that we enjoyed and saw being on site.
I think the benefits to being on site are really endless depending on what your level of convenience is. For us it worked out really great. We could go out early in the morning (and sometimes catch the EMH) to the parks and come back for a swim or rest in the afternoon. Maybe head over to the Boardwalk for some shopping/enternainment. Then wed head out for some really nice dinner and then back to the parks for some night time fun or over to Downtown Disney. When youre offsite you dont do this. You get up early (to not fight the crowds) and drive over to a park. When youre tired/exhausted you leave the park, find your car and drive back to your hotel.
I know there are people that for some reason dont see the benefit in staying on-site. Its their choice and I respect it. I think though that those people have never actually stayed on-site for more than 2 or 3 nights. From the posts that I see on this board and our experience is that once you stay on site its really REALLY hard to go back to staying at a hotel off-site.
We were back in 2005 with our DS and DD and again we stayed on-site. This time it was at the Dolphin. Yet again we had an awesome on-site vacation. In 2008 we are planning a trip to the Beach Club as we seem to love the Epcot area.
For us (unless it wasn't possible financially) when we stay at Disney it'll always be on-site for sure. I really cant imagine it any other way.
) and she was only staying for one night! I think she was being overly critical, but she says not. The hotel itself was very nice. She said she just felt totally disconnected from the Disney experience and was very happy when she arrived at her WDW hotel. 
Thanks Amanda. We definitely get that feeling when we drive throught the WDW gates/banner. Definitely a nice feeling. 
? It is magic and a little piece of heavenly happiness even for a short time
