We haven't used it yet - we just joined in Feb - after many years of debate and trips anyway. We are a family of 5, and are DEFINITELY looking forward to the extra space a 1 BR provides. As a family we have gone to WDW annually since 03 - twice in 05, with several mini-trips along the way. I took both of my sons on separate F/S weekends in 04 and 05. We honeymooned at the Grand Flo, and then back on a couple of occasions before the family trips began + several solo visits while in FL on business.
Similar yet different than what others have said about DVC in other threads and on the DVC DVD - it's not that I wished we'd known sooner - it's I wish we been able to join sooner. I first started inquiring about DVC shortly after our honeymoon - but finances just didn't allow. A couple of trips have been on points so we stayed at the Hotel Plaza or off-site. 1 trip we won in a contest, and the rest were cash. Regardless of how we got there - we did, and as the kids have grown, their own desire to return has grown. We're excited about how we're going to use the membership.

We took the tour for the first time last Sep as a family while at POR (nice, but CRAMPED!), but DW wasn't 100% sold just yet. I was back at WDW on a business trip in Jan (conference there, and of course I took some time for myself in the parks, etc), and took it again then. By that time DW was sold and we knew we were ready. We bought directly from Disney and got the Developer Pts. incentive. Looked at resales, but we wanted AKV - so getting the extra points made sense for us. Plus it allowed us to have enough points to get a 15 yr anniversary trip planned for next March in addition to next year's vacation!
My biggest wish was that we had been able to get more points from the get-go!!!
Addonitis has already struck. But, we're waiting for DL's GCV before we add more points. My DW, oldest DS and I are native CA 'ians and have lots of fam & friends out there, + my employer is based in So. Cal - so we get out there regularly too. Having home resort on both coasts makes sense for us.