I love Main Line Ob/Gyn and Paoli. All 3 of my babies were delivered by Dr. Krell at Paoli. I needed a c-section each time, and I did end up with some serious complications after my last. Everyone was absolutely wonderful, and I truly believe the care I received saved my life (the complications were not due to medical errors, etc.). The maternity nurses at Paoli are superb almost without exception, and the unit is very family-centered with larger rooms (usually private as well).
As for Main Line ObGyn, I love Dr. Krell and have been lucky enough to have "my" doc deliver all of my babies. I did occasionally see some of the other docs though, and I also like Dr. Manfrey. I've actually always received good care from all the docs in the practice, but Krell and Manfrey are the ones I have the most experience with.
I don't think you can go wrong with Paoli or Main Line Ob/Gyn. Good luck with your choice!