We just bought our first contract resale (not even through closing). I would agree with other posters that the benefits of the direct buy aren't really worth the doubling of the initial cost. Buying direct seems to me best for someone with a "cost is no object" attitude.
The ability to use points outside of DVC for cruises, other hotel stays, etc, seem nice on the face of it, but Disney basically screws you when your doing this by giving you a VERY poor value for your points. You are much better off renting your points on the rental market and paying cash any of those things. Again, if how much a trip actually costs doesn't matter, then using the points this way is just fine.
The other benefit is when buying resale it takes a while (3 months) to actually get the points. If the extra money is not worth your patience, then buying direct may be better.
As others have pointed out, to me a HUGE benefit of buying resale is that you could sell again in the next few years without taking a giant bath. For instance, we just bought a resale contract from someone at AKV for 160 pts for $74/pt. Searching the history, they bought it in 2009 for what looks like $112 a point. This means that contract cost them $6000 for the 6 years they used it. Now, if I sell that contract six years from now, while I can't predict the exact price, I would probably be able to sell for between $70 and $85 a point. So whereas that contract cost them $6000 for 6 years, it might cost be nothing for six years.
Since my plan is to use my contract to the bitter end, that doesn't really factor for me, but it DOES on the YNK scale (you never know).