We bought our initial points in March 2001, a small add-on in June 2001, and then another add-on sometime in 2003.
As far as the purchase transactions went... All were purchased direct from Disney. It was all very simple. They FedEx'ed the documents with return envelopes. We paid for the purchase by credit card - not a hitch. In one situation, FedEx lost the documents that were sent back to DVC. In a couple days, they sent up a replacement set and it all worked out in the end.
We have our dues paid by CC - all very painless (except for the credit card company's mark-up on the exchange rate, but that's *another* topic! LOL).
Looking back, if I knew then what I know now, I might be more willing to purchase via the re-sale market rather than direct from Disney - I would probably have to learn some patience, though! The big advantage to buying direct is that it is no-fuss. It all can happen very quickly: you say you want to buy and they send the papers. Once you send the papers back you can book a vacation using your current year's points (can't bank/borrow until the deed is registered, which seems to take ~30 days - that is not under Disney's control). Resale may/may not be cheaper, it depends on a variety of factors, but you can get properties via resale that you can't get from Disney (i.e. if you *really* want to own @ OKW, the resale market might be your only real opportunity). Resale will definitely take longer - you must wait to see if the vendor accepts your offer or it passes by Disney's ROFR time period.
As far as the concept of DVC itself. No complaints. We find the flexibility to be fantastic... Not tied to any particular time of year, not tied to any particular room size - you probably already know those benefits.
HTH, Jeff