I had just written about how much I disliked the AirBART-- mostly because of the terrible experiences I've had waiting and dealing with the unsafe surroundings. Again, maybe I've just seen the worst of it. I will always prefer to drive to OAK from Orinda unless there is a major pile-up on 880 or Caldecott Tunnel.
Personally, I don't feel the need for direct BART access to OAK. It would be GREAT to have, like the SFO connector, but when it comes down to it, is it necessary for me? No. But perhaps passengers living in Dublin, Concord, Pittsburg, and especially those at the other end of 80 freeway in El Cerrito, might find it very helpful as it will help them skip the major traffic pain points.
I've been very negative about the Coliseum BART station but let's focus on the positive for a moment. There is no easier way to get to an A's or Raiders game. I only wish it was that easy to go to a Giants and 49ers game. The MUNI connection going to AT&T Park is not terrible but it is a cluster ****.
Will a BART OAK extension increase ridership? I can't say but I sure hope BART has done their research and are certain that this is a project worth pursuing.