We were given a free upgraded to a BC suite during a slow September trip 3 years ago. We have also taken a tour of the BCV 2 bedroom. In our opinion, there was no question that we liked the BCV 2 Bedroom better.
The BC suite was very beautiful and much larger than the regular beach club room. The extra room was pretty much a day-bed room that opened onto a larger than average balcony. Between the room, two french doors led to the bedroom with one king bed. This suite was perfect for husband a wife, but would not have helped very much with a child because of the lack of privacy with the french doors. The bathroom was also a little larger than the regular room.
However, we felt like the BCV 2 bedroom was much nicer. The master bath is amazing with the jacuzzi tub and pass-through window into the master bedroom. The decor is a little more subdued than the regular BC rooms, which we really liked. And the full kitchen is beautiful.
Although we didn't get to stay at BCV at the time, we liked it enough that we are renting points at Saratoga Springs this September for a 1 BR with a wait list for BCV 1 BR. We are also taking this as our information gathering trip to decide if a DVC purchase is right for us.
By the way, the 1 BR has the same master bathroom suite and full kithen as the 2 BR.
The main down side to BCV (and for us, it is a small down side) is that you cannot get a view of the lake and the boardwalk from your balcony. The other down side is the less-frequent room service. In the suite, we had regular room service plus priority turn down service. At BCV, you get one or two regular services per trip (I know this is true for DVC members and people who rent dirctly from DVC members. If you rent directly through disney, you may get once a day room service. I would ask to be sure).
Hope this helps....