What I learned from my experience at an attempted VBAC is that you need not just a supportive OB/MW, but a supportive practice and hospital. So I would run far, far away from not just that OB, but the whole practice.
My OB was very supportive of my attempt at a VBAC even though I wasn't considered a good candidate. I ended up with a long and painful labor, just like with my first, but this time around, I felt like the doctor on call and the nurses had written me off as a repeat c-section. I got no support at all from anyone on staff. I had delivered at a different hopsital with my first (we moved, so I had to find a new OB and hospital) where I felt like everything possible was done to help me have a vaginal birth and even though I was disappointed I ended up with a c-section, I was at peace with the decision. When I told my OB at my post-op about the lack of support I got, she admitted she was afraid that was going to happen. What?!
So now I tell my friends considering VBACs to not only find a supportive OB/MW, but to ask whether others in the practice support VBACs AND to ask specifically how the hospital supports VBAC patients.