This is a hard decision. When DH and I bought, there was only OKW and BWV. We had seen models of both, and basically said to ourselves "if we came here for the next 45 years and could never stay anywhere else except our home resort, could we be happy at OKW?" The answer was yes, the cost wass less, the dues were less, and the points were cheaper to buy, so we bought at OKW.
My opinion/observation of the DVC resorts:
OKW-largest rooms, condo style with exterior entrances rather than hotel stylepark in front of your unit (or pretty close), tropical theme with light furniture-lots of pastels, boat to DD, bus everywhere else-some folks have negative things to say about bus service such as long wait etc but I have never personally found this to be a problem, one on-site restaurant with decent food, nice main pool but no special theme or attraction(ie-slide), 3 quiet pools, all pools with hot tubs, snack bar near one quiet pool which is open sometimes depending on time of year, snack bar and a small regular bar near main pool, rent various recreational things(boats,bikes),arcade near main pool,large spread out resort(can be a + or a - depending on your perspective),relaxed atmosphere, nice views from most rooms as it is located on a golf course, and the landscaping is the most mature since it was the first one built.
BWV-smaller rooms than OKW but amply sized for a vacation condo IMHO, hotel style with interior entrances off of the hallway, some people have commented on long hallways but I haven't found that to be a problem personally, seashore themed with lots of blue used in the decorating, great location with access to all the Boardwalk stuff, plus walking/boating to Epcot and MGM, bus to all other parks etc, bike and boat rental, main pool with a slide themed like an old-fashioned wooden roller coaster where you come flying out of the clown's mouth, snack bar near main pool, 1 or 2 other quiet pools, all pools with hot tubs, lots of activity, I am not sure if BWV has an arcade, but there is one at ESPN and over at the BC, so they are close by if not right in the hotel, valet or self park-we valet, mostly good views from most rooms, but I am the type that likes the front entrance view because I like to watch the comings and goings, so take my opinion on views for what it's worth!
BCV-smaller rooms than OKW but amply sized for a vacation condo IMHO, decorated in a beachy theme-light and airywith lots of pastels, location within walking/boating distance to Epcot/MGM, bus to all other parks etc, bike and boat rental, main pool is Stormalong Bay which is second to none in terms of hotel pools at WDW, snack bar near main pool, has several nice restaurants(Yachtsmen Steakhouse(steak), Yacht Club Galley(mixed menu),Cape May Cafe(seafood concentration with a character breakfast and a dinner buffet), Beaches and Cream(old-fashioned soda shop-light snacks, burgers,great ice cream!), hotel rahter than condo style with interior entrances off hallways, valet or self park-we valet and find that it's not a far walk at all since you don't have to walk into the hotel to get to the villas, I have heard that there are some not-so-good views here, although the 2 times I have stayed here we have had a pool view and a woodsy view.
VWL-smaller rooms than OKW but amply sized for a vacation condo IMHO, decorated ina rustic theme-deeper colors but very cozy,boat to MK, bus everywhere else, IMHO the bus service from this resort has always seemed slow, bike and boat rental, main pool is quite nice with little waterfalls and rock outcroppings and a geyser that shoots off very 30 minutes or so which is neat, there is also a quiet pool, has a nice restaurant (Artist's Point) which serves Pacific Northwest style fare-venison, rabbit etc, has a fun casual restaurant(Whispering Canyon)with good food, also has a nice snack bar near the main pool, hotel rather than condo style with entrances interiorly off the hallway, valet or self park-we valet, this is always a very serene-feeling resort to me, have heard of some not-so-great views here, although most views are woods or pool...there are a couple of dumpster views though!!!
Think about location, think about cost, think about how you vacation now, think about you would like to vacation in the future, if you have children remember that they are not always going to be young, remember it is willable so SSR may be good because if something happened to you you could leave it to oyur children and they'd have use of it for 12 years longer, consider how many points you'd like to buy, don't say that you'll buy enough points to stay in a studio, because once you stay in a 1BR, a studio(even though it is nicer than most hotel rooms!!!!)is going to feel like a step down. You get spoiled by the full kitchen,jacuzzi tub, washer dryer in the 1BR and larger units.
IMHO, there is no bad WDW DVC resort...I could be happy in any one of them. But, if you are going to spend the money, you may as well try and pick the one where you think you'd enjoy the most.
Hope this info is helpful. Good luck!!!!!!