Generally, it is a good idea to buy points at the "home" you are likely to stay at most often. It clearly gives you an advantage of time if you plan properly and well in advance.
One thing many Members do is to split points between two or more "homes". If you can afford it this may be an option for you.
My "home" is OKW since I bought back in 1994. I have stayed there the most, in both studios and 1-bedroom units. I have also stayed at the BWV (studio), VWL (studio), HH (studio) and now VB (studio). During visits I've seen models of the larger units available at BWV and VWL to compare sizes and amenities.
OKW units are the largest of all and most convenient in terms of parking since you can generally find spaces near each condo. The Resort is spread out and has a relaxed feel to it. If you are looking for big, fancy pools and lots of activity this is probably not the "home" to select. If you enjoy golf, nice but quieter pools and activities this is perfect. Laundries for studio guests are located at the pool areas. I always use my car to travel to parks and such when I am here. There is bus service available to locations around WDW but I hate to wait &/or have to switch transit to get where I am going.
BWV is a large Resort. Because of that your unit may be located at the end of a VERY long hallway, as mine was. When you need to lug groceries "home" that may be tiresome. Parking is another issue. If you choose to park yourself, it may be a long hike from the car to the Resort. Efforts are being made to help the situation but day guests still take up spaces until Epcot closes. The units themselves are very nice. My studio, though the setup was different than at OKW, was spacious enough for me. The porch was small however. One laundry room is down near the BW and very busy. Having the activities of the BW right there and access to Epcot and MGM (by boat) is excellent and a big selling point.
VWL was beautiful, IMO. The units are about the same as at the BWV and very nice but a bit dark. The Resort isn't so massive that you need to hike endless halls to your unit. Parking is in one big lot so you still may be off a distance there. Having a few restaurants on-site and within the main Lodge is convenient, especially in bad weather. If you will visit the MK or use the monorail often, the boat transportation is very nice to have on-site. Set on a lake, you have easy access to water sports and fishing. There is a hiking trail too. If you are looking for a relaxed, natural setting with a beautiful pool this is it.
HH is another relaxing, natural Resort. It's quiet and perfect for guests who enjoy biking, kayaking, birdwatching and such. There are restaurants within walking distance and excellent golf and tennis facilities across the Island. Private beach access is a walk or quick bike/car ride away. Parking is close to each condo or the Main Lodge. My unit seemed a bit larger than at either BWV or VWL and the porch certainly was spacious. I have heard that larger units have working fireplaces. Units are rather dark though, in keeping with the setting. One laundry room for studio guests is located at the Main Lodge.
I stayed at VB for the first time two weeks ago. My unit, in one of the Villas, was exactly like an OKW unit. From what I could see the 1 and 2-bedroom units are also, at least in the Villas (not sure about Inn accomodations). Porches are smaller, however. Parking and laundry facilities were conveniently located and the Villas (Inn too) had an elevator. The pool area is very nice but for me the main draw was the beautiful beach steps away from my door. Two restaurants, a snack stand and a bar are on-site if you don't want to venture out. Plenty of great restaurants and places to visit are within easy drives. WDW is about a 2 hour drive away so this isn't the place to stay if you want to be in Orlando very often. If you love the beach and simple, natural settings and activities this is a great "home" to select. Many Members split a stay between this Resort and days at a WDW "home".
As for the new BCV, I have yet to stay there. I have heard nothing but good things about it though. It offers convenience to get to the parks and BW with the added attraction of nicely appointed units. The pool is suppose to be excellent and the Resort is not as massive as the BWV.
With the non-home Resorts I was able to make reservations within the 3-7 month window. At BWV I was waitlisted at the 7 month mark (for May). VWL I booked at 7 months out, no problem (late April). At VB I just managed to get in at the 3 month mark while HH was booked solid well before that (for May). I travel at off-peak times, generally late April-May, October and early December with a "use year" of September.
Tour around, if you can, and good luck in your decision.