Charlie - Are you kidding about wanting more info or did you not read my last post in the string? I copied a good deal of text from the Boston Harbor Islands brochure in my last message. Either way IMHO Peddock's is the best as you have good access to Hull Gut. Any of the islands are great, especially overnight. The view of Boston from one of the islands at sunrise or sunset is beautiful, it's hard to believe something like the harbor islands exists so close to the city.
Another note: I believe there are ferry services from Hull to Georges or Grape islands. Check with one of the local tackle shops to be sure but it might be a better option if you would otherwise drive into the city and keep your car overnight in a parking garage for $60.