We've got two contracts, one we bought from the developer and one we bought on the resale market. I would do either again.
I'd buy from the developer again if the prices were fairly close on a newish resort, for the lack of hassle and ability to use the points much sooner. I found buying resale more stressful, so given a fairly minor price difference, I'd definitely buy from the developer. I can also be tempted by really good promotions. I was really tempted by the free cruise promotion, for example. The timing was wrong for us, but if they offer it again, I'll probably be buying.
If we decide to get a handful of SSR points for those trips that we plan within the 7 month timeframe, which we have considered a couple of times, we'd almost certainly buy resale. When the price difference is that extreme, I really can't see buying anything but resale.
We know we're going to get more points at some point in the next couple of years, but we don't actually need the points until 2012 or 2013. So I'm going to keep an eye on current promotions. I'm also keeping an eye on resale prices.
I admit I'm curious about what they're going to do with the tiered system. Not that I want to bring that thread over here, but if they manage to make the perks actually useful to me personally, it might make me more likely to purchase points that would get me to a particular level.