I agree with what Deb said above, and also what Bill said.
DVC can't be beat for WDW. We've made about 30 DVC trips to WDW and enjoyed every one. But I would make that more specific and say
ONLY for WDW.
Anywhere else, IMHO, something else (Marriott, Hilton, Wyndham, etc) will be better. I don't own Marriott and don't really know much about them, except that their resorts and system are highly regarded. Same with Hilton. I can't say personally, but I've seen many comments saying that at least some Marriott and Hilton resorts were better than DVC.
I do own Wyndham, so I know and like their system and all of the resorts I've stayed at have been great.
To me, the big difference between DVC and Wyndham is that DVC has 13 resorts, 9 of which are at WDW -- and Wyndham has at least 105 that I can access with just a basic membership...in 25 states and the US Virgin Islands. We spent two weeks in AZ this summer, most of it at Wyndham Sedona and Wyndham Flagstaff -- two great locations where DVC has nothing. We're now planning trips to Northern California and Washington DC, both places where DVC has nothing. And for WDW, Wyndham has 5 resorts in the WDW area, including 2 which probably compare pretty well with DVC.
So, if your vacations every year for the next few years (10 or so) are going to revolve around WDW, I think DVC is hard to beat. If you only plan on going every other year, every third year, or less often...I would really think long and hard about DVC.
I think it's also critical for folks to really think seriously about whether ANY timeshare -- with their ongoing annual financial commitment, whether you use them or not -- is really the BEST vacation alternative for their family's specific needs.