We are AP holders, and with that you can get a better room only rates when available. I have found by calling to make your ressie that normally you get a better price. But first look on line at the price before you call, I have had a CM say that is the AP holders rate, but it was the same as the rack rate listed on line, so when I questioned it she said it wasn't available, so I did not book, when I called back the next day. I was able to get the AP holders rate which saved me around 50.00 ( a night) at a moderate. I don't know if one day mattered but...just saying... as a suggestion.
Depending on what AP you get some offer free parking in the park lots.
When comparing off site <to> on site = there are a lot of factors to consider and
most of all what's important to you for your trip.
How do you normally tour? Rope drop, early morning breakfast with the characters


, late night parade and fireworks

.
Time - in the parks -vs- time in the car to and from the parks, parking, driving sitting in traffic at the end of a long day

or early morning when trying to make rope drop

..
For us staying on site is the way to go, while most of the time its a bit more expensive, for us well worth it. No driving, DH drives a lot with work

, so for us this an important factor. We both love that feeling you get when you pull into your resort

, knowing your on vacation whether for a long weekend, one night or a whole week. The theming is another plus for us, nothing says Disney like the Resorts, the rooms, landscaping, the pools. Waking up knowing your at Disney

is another biggie for us. The excitement when the bus pulls up and we see Magic Kingdom

We love knowing that if we want to head back to the room for a nap or pool time it is just a bus ride away. Also if we want to have some adult beverages over in Epcot we can without worrying about driving

back to the resort.