I have tried disposable underwater cameras with ISO 800 Fuji film and they worked great, however, I prefer digital mainly because I travel to many remote locations with nothing but a backpack and a canoe, to get 500 pictures of digital quality, it costs me less than a quarter ounce in weight (memory card) however, 500 images on film is a lot more weight - you can see why I choose digital.
As for testing the bag, I have only had a chance to test it briefly indoors for 3 pics, close up pictures turned out nice - no indication that the bag was there, the one pic that was of a general room was blurry - could have been operator error, I will have to report back after further testing - stay tuned.