For this year, I would go for the August Dates. Due to the construction of Star Wars Land, they have had to reroute the train tracks and the River of America. That has caused some significant closures–the canoes, Tom Sawyer Island, the Mark Twain river boat, the Pirate Ship Columbia and most importantly, Fantasmic. Disney is scheduled to reopen all that “Summer 2017”. I would go later in the summer so that those attractions are reopened. That will help disperse the crowds to more areas of the park, thus reducing wait times throughout the park. Most importantly, if you haven’t seen Fantasmic at Disneyland, its way better than at WDW (not knocking Fantasmic in Hollywood Studios, but you have to see it at Disneyland)!
If you do wait til August and the Rivers of America is reopened, check for Fantasmic Dining Packages. They have in the past been an excellent deal. If they do offer it with the Blue Bayou, there really is no other choice. That Restaurant is Amazing and if you time it right, you can sit inside by the water and watch guests start their journey on the Pirates of the Caribbean!! My kids love that! It adds a great atmosphere to go with their amazing food!