I think your assessment of the fellowship is mostly right, but I do have to take issue with a few comments. First, our last fellow got about 800 - 900 cases as primary surgeon, so I don't think the 500 -600 mark is accurate. He was doing 10 vits/day, and not all straightforward ppv/mp's either.
Regarding Dr. Ambati, once you get to know him, he is an amazing person with great insight into retina, and also is extremely well read on world politics, etc. He is one of my favorite attendings because he makes you think. I would be more put off by someone who went through the motions during an interview process than by someone who challenges you through tasks and difficult questions. If anything, that shows he is more invested in the process of selecting people by truly getting to know how people react in certain situations. Just my $0.02, but I think you would be hard pressed to find a resident or fellow who doesn't like Dr. Ambati once you get to know him.
I am not applying for retina fellowships, so I don't know how to compare this program to others, but I will tell anyone interested that you get a crazy amount of surgical and clinical experience with some of the nicest and most personable retina guys around in Drs. Pearson, Blackburn, Stone, and Kitchens. I don't know Wood or Isenhagen, so I can't comment on them. Hope this helps.