It seems that all two bedrooms are a one bedroom and a studio, so what's the difference between the two, do the dedicated two bedrooms have a connecting door that lock offs do not? It's the only thing I can possibly thing of!
A 2-bedroom lock-off is a Studio and a 1-Bedroom with a connecting door. The Studio is your 2nd bedroom.
A Dedicated 2-bedroom can only be reserved as a 2-bedroom. It will usually have 2 queen beds in the 2nd bedroom. There will be a single entrance door to the room.
a dedicated 2BR is not a studio + 1BR. it is what it says: a 2BR only. there's only 1 entrance/exit door...there's no door that can be locked off in the middle...there's no kitchenette in the 2nd BR (what would be the studio side in a lockoff).
MOST lockoffs have a queen bed and a full pullout sofa (like studios - at OKW studios and all two bedrooms have two queens). MOST resorts (but at BCV not ALL) two bedrooms have 2 queens in the second bedroom.
Generally lockoffs seem to be preferred when you have another set of adults (or family) travelling with you - they get their own door, their own coffee maker. When people have young children they worry about escaping, they sometimes prefer a dedicated. The dedicated also has the two beds (again, usually), which is nice.