I'm afraid I must jump in and say something about the PETA "investigation" if you can call it that.
I would take everything they say with a grain of salt. I did alot of research on PETA and that particular study for another website, and found alot of their "facts" lacking. Their "videos" shady and touched up/edited, and overall bad info given.
I actually met someone who worked at Iams after PETA's "investigation" (which was a number of years ago, btw) and who adopted one of the dogs used in the studies. She said it was never as bad as they say and dogs are socialized, trained, and kept in very nice conditions. I won't go into exactly all the info, but just remember that you really shouldn't take PETA at their word.
I do have Gunther on Iams, and when I can afford it, I am hoping to switch over to a higher quality food that isn't going to break my bank. Right now I am needing to switch Keiko's food (again) to hopefully something slightly cheaper, but still good quality so that I can move Gunther to a more expensive, higher quality food. One that is still available at major realators, I might add, as we will be living in the boonies and I'm not sure what other options we will have.