I won't count the times a Hooligan has been on vet prescribed foods for an extended period of time (LR for Kelly and Venison for Mac), just the major changes.
When I moved to Florida in 1995 I was feeding the Hooligans Pedigree and happy with the results. They changed the formula, and the puppers started looking bad with dull coats, etc. so I switched to Innova.
I fed Innova for about 8 years with a one year interval where I fed a complete, frozen, raw diet which I liked but could not afford since it ran a little over $500 a month. Okay, back to the Innova. Again, the dog's coats started looking poor, I found out some minor changes had been made to the formula so I switched to Chicken Soup.
I was happy with the Chicken Soup until a couple Hooligans started having gunky ears which I took care of with Zymox and one was getting a dull coat. I found out that the formula had been modified so I switched to Eagle Pack Holistic fish food which they're currently eating and so far doing well on it. I changed wet food recently to EVO since I had been looking for a 100% meat formula as a little treat at meal time (it's 95% meat which is the best I've found) but they only share 1/6 of a can so they don't get much.