I would take an afternoon or two and explore all of the different resorts on your own if you have a chance...
Each resort is great, and I don't any would be a wrong decision...
Some things to consider while looking though...
1) The rooms at OKW are a bit bigger, and IMHO make better use of space..
2) OKW and BWV are the only two onsite resorts with Grandvillas.. (SSR will have them as well..)
3) BWV is the only resort where you can reduce the amount of points you are going to spend on a stay by requesting room with a "Standard View".
4) BCV and BWV are within walking distance to Epcot and MGM..
5) VWL is the only
DVC resort with boat service to the MK..
6) Currently OKW is the only dedicated onsite DVC resort... SSR will be the 2nd dedicated resort once it opens.
7) BCV has one of the most popular pools at WDW with Stormalong Bay...
8) As already mentioned, the contracts for SSR expire on 2054, whereas the other resorts expire in 2042. (12 extra years of use..)
DVC will naturally try and recommend that you purchase through them for either a contract at SSR or at VB so that they get the sale... (My DW and I took the SSR model tour and were really impressed with the room decor and layout... So much so that now we are considering another add on..

)
The biggest piece of advice you hear given on this board is: "Buy where you want to stay..." These are words to live by when purchasing...
The only way you will know which resort suits you best is to research on your own ahead of time...
After you feel comfortable with a specific resort, I would only then either go to DVC for the SSR presentation, or contact a reseller.