You can get a specific list of the benefits from the website but here are some of the things I have experienced:
$1 Disney Dollar for every $100 charged on the card.
This has been GREAT for my family. Every year, we apply the Disney Dollars toward our trip. You can use to to pay toward your reservation, spending money or towards your charges to your room. We use our Diseny Visa as our primary credit card so we are sure to build up a fair amount of Disney Dollars each year.
Discounts on Shopping / In and Out of Parks
You get a discount when you check out at most stores at WDW or the
Disney Store. Ask for the Disney Visa discount when checking out.
Character Meet & Greet and EPCOT with a free photo
Its done at Innoventions West during a certain time of the day, everyday. When I went the characters were Mickey, Minnie and Goofy, so it's great characters. Plus you get a free photo of the event.
Special Perks upon Announcement
I know there is a discount running right now for Disney plays on and off broadwy (Mary Poppins and Lion King)
Check out the Disney Visa website for more.
I would recommend the card. We have made good use of the perks. Hope this helps!