I don't think we have anything that complex, but here's a very recent poll on 5+ years owners and their satisfaction. 73% are as satisfied now as they were in 2002 and about 1/4 were less satisfied. Given your interest in the topic I thought you might like a link to the comments. DVC Veteran Owner Satisfaction Poll
Bought OKW in 1996 - sight unseen, with a group of family members, some of whom had taken the tour. It has definitely been a good value and lots of fun for us.
Best part was - since we bought sight unseen (other than watching a video) and we were sharing points with other family members (4 families each with 55 points/year), we had never even seen a 1-bedroom. Staying in a studio was great...until we shared a 2-bedroom one year. Then we had to do an add-on.
I messed up and voted 7-8 years but we are really 5-6 years... Bought in Feb 2001 added on in March 2001 and again when BCV went on sale when ever that was... lol