IF you goto WDW at least once every 2 years, if you like staying on site, if you see yourself continuing to goto WDW once every 2 years, if you would like to stay in 'nicer / bigger' places at WDW if you like having a kitchen / washer/dryer etc etc then for sure look into DVC..
pluses on DVC (in my eyes, and some of these could disappear at any point)
discount on AP. If you plan it right you can get 2 trips in one year for one AP ie: 3rd week in OCT this year, 2nd week next year..
if you like to eat at WDW and also have a drink or 2 or 3.. the Tables in Wonderland card is AWESOME. gives you 20% off the whole ticket including drinks (at almost all disney table services)
if you pay cash you are prepaying for xx years stays, minus your maint fees of course
no tax charged on rooms (can add up if you would be staying peak times or at deluxes on cash)
minuses
maint fees, they will and do go up, so you really do need to look into that
you are locked into WDW, yes you trade out, but from what I understand it's pretty bad compared to other timeshares.
no daily mousekeeping (a minus to some, to me, doesnt matter)
really for ME and MY FAMILY these are the only downsides that we have found. I know for others they have their own lists. You'll have MANY people say "I dont want a kitchen, I'm not cooking while I'm on vacation!! or I'm not doing laundry!!!" That's fine, for US those are positives.. dont have to take nearly as many clothes (unless you insist on having a different outfit for everyday) you can save on food if you dont mind cooking / taking the time to eat (the taking/making the time to eat is hard to do lol, the cooking part is easy
)
So we own.. We bought thru WDW AKL in 2008 or 09. have done 3 trips on DVC, doing 2 this year, then wont again til Jan 14 (marathon!!)
If you look at CASH prices, in the next couple of years we will have 'broken even' or close to it on the initial purchase, then all we are paying for our rooms when we goto WDW is our maint fees so if our maint fees are $1200/year we have points to do one trip a year in our 1 bedroom villa.. comes out to about $172 per night for a deluxe room.. Again, no taxes on that. Now that will go up over the years, but usually so do room prices..
That's MY simple minded thoughts on why we bought DVC.. right or wrong, that's our reason. Oh and my brother bought a year or two after we did..