My parents own at Marriott, so those were the resorts we stayed at for many of my
Disney vacations. They're beautiful resorts, and we always had wonderful times.
When I began looking at buying my own ownership, I was somewhat biased toward Marriott myself. My father made a comment once about the fact that
DVC ownerships expire, and I was certain I didn't want that.
Before we bought, we took a trip on our own and stayed at the Wilderness Lodge (on a cash reservation). I was sold for life to want to stay on site.
We really enjoy getting on-site perks; Magical Express, Disney transportation, extra magic hours, dining plan are all very nice. We don't use them all on every trip, but it's nice to have them available.
When we're staying at SSR, there isn't a big transportation difference between onsite and Marriott. We need to take a bus back at night, or take the same shuttle out to the parking lot to take our car back. It takes just about as long as getting back to the World Center area. However, when we're staying at Beach Club, Boardwalk, Wilderness Lodge, or (soon) Bay Lake Tower, I can tell you it's a lot nicer to be right back at your room than to have to drive back to an off-site location.
I think Marriott now has more flexible options, but the plan my parents have is for week-long rentals with limited check-in days of the week. I really like the fact that DVC allows you to choose the length of stay you want, and any check-in day.
My parents also have limited flexibility for room size with their Marriott ownership. They have a 3-bedroom unit. They can split one week into two by using their lock off separately, but I find the DVC ability to use points for whatever size unit you want a lot more flexible.
As to the ownership expiration, the more I thought about it, I realized that I'll be 90-some years old when my membership expires. Even if I did have kids, I'm not sure it would be that valuable of an asset to pass down. What would the material condition of a resort that old be -- the annual dues would be very high.