I used Disney for my photographs and they did a wonderful job! My only "regret" with the pictures is that I didn't ask for specific pics or even ask for more. Mostly because I usually don't like pictures of myself anyway!
Our photographer was easy to work with, made the pictures "fun", and really tried to capture the very casual spirit of our wedding.
I know a few others had the same photographer and he did a fantastic job for them as well.
The biggest gripe I hear with Disney is that you cannot choose your photographer. So you really don't know if the one you get has the same "vision" as you. I think many of the photographers try to help with that by talking to you before the ceremony (mine called the night before to talk to me and find out if I had anything special in mind...I just missed his call!)
Most of the brides here have used an outside vendor (Randy Chapman) and have been VERY happy with his packages. For me, the extra cost of having him added to my intimate package was just more than I could afford...so I stuck with Disney and was not disappointed.
Are you having an intimate wedding or a custom? Sometimes that can make a difference in your decision making...
My only advice if you choose Disney is to PRE-PURCHASE your proofs. (Last year they were $225.) And, if there are any specific images you want (special poses, etc.) make a list and give a copy to your EM, then make sure your photographer is given a copy when he arrives.
Also if you use Disney (and are not a UK bride), you can purchase the hi-res CD of your photos for $1000. I think this is where most brides think Disney is too expensive. However, you can wait three years and purchase the same CD for $99 (which is what most brides who use Disney seem to do, I know I'm waiting! 2 more years!!!

) Until you have that hi-res CD Disney still owns the rights to your images. You will not be able to have copies made or printed anywhere until you have that hi-res CD.