We almost got suckered into this as well and luckily things didn't work out for us, here are some key differences:
- DVC is more of a membership that has a set end date, the Hilton version lasts forever. While lasting forever sounds like a good thing, keep in mind when they say forever, they mean it, so your great, great, great grandchildren could still get stuck paying annual dues for something that at that point is useless and will be unable to even give them away.
- It is pretty much impossible to trade into Disney Owned Resorts from a non-DVC timeshare, because everyone wants to go to Disney. On the other hand, if you have DVC, you can pretty much get an instant confirmation that a trade through RCI has been approved.
- Hilton does have some nice resorts near Disney, some of which even have shuttles, but they do not get Extra Magic Hours, etc.
- At DVC resorts, Bell Services will handle your luggage (at the Grand Californian, they will even unload your car for you), yes you need to give them a tip for doing so, but still nice. With Hilton, there are no bell services, you have to deal with the luggage yourself.
- With Hilton you are expected to leave the room clean and tidy for the next guest, including making the bed, vacuuming, etc. and if you don't there is a fee of $50 to $150 per room. DVC does not do this.
As for buying direct or not, it depends on what you are offered, with DVC, you can often get enough in incentives to make it pretty close to the resale market these days, especially if you buy while on a cruise (probably the best time to add on points unless you are a cast member, as they get a pretty good discount from what I have been told).
I am not saying Hilton is or isn't worth it, but I am saying that if you go to Disney on a regular basis, DVC probably makes more sense.