If I were going to do it today, I'd rent points from David rather than buy in. Its a little more expensive than buying in, but the flexibility gains are huge. As long as David has an owner, you get the eleven month window where ever you want it. If you don't want to go to Disney for three or four years when the kids are in high school because their schedules are busy (and I can't believe how busy my daughter is - my son is more of a slacker), you don't have to go renting your own points or finding another use for them. If you hit a financially rough period, you don't have dues payments.
When we bought in, all rental deals were between individuals, a broker provides a little extra security. And when we bought in there where only three onsite resorts (BCV was being sold, but wasn't yet built) - five total - yeah, it was hard to get VWL for Christmas (we don't travel at Christmas) or BW for Food and Wine (we own Boardwalk) or an OKW Grand Villa over Easter (again, don't go over Easter), but there wasn't the insane competition for those things that there are now with three or four times as many members - and the same number of BWV Standard rooms for Food and Wine. So while the advice has always been some version of "buy where you want to stay (and plan ahead)" that advice has become, I think, more pertinent, but its also now very apparent that you can only buy what is built at the time, you'll still have the "I don't own there" problem with new resorts, unless you are willing to own a lot of contracts (I'm not).
The other thing that's more obvious to me with time is that both Disney and my family and I change. When we bought, we went to Disney in part for the food - that has slipped while at the same time our own dining tastes became more refined (or, if you prefer, we became food snobs). I'm not really interested in the pace of technological change that comes with FP+ - I go to Disney because it was EASY - we knew how to work the system - now we are back at square one, and I'm not that interested in square one. My kids prefer other locations as teenagers - my son, the beach, my daughter - anywhere with good museums.