I worked at Arby's for several years. I can attest that the quality of Arby's can change DRAMATICALLY from store to store. It all depends on the owner and the management. A microwaved McDonald's hamburger is just as tasty/untasty as a microwaved McDonald's hamburger at any other restaurant. There is just so much standardized at those restaurants so many things taste pretty much the same. But at Arby's much of the food prep is still hand done. One of the biggest effects is the thickness of the meat slices. A sandwich with very thin slice of meat tastes great, but takes longer to prepare. The same sandwich with meat slices twice as thick is much quicker to prepare but the texture and taste are quite different. Does the manager want quality food or fast service? As another example, the time that Arby's food sits out will vary dramatically from restaurant to restaurant. It isn't like McDonald's where the food flies off the shelf so quickly that there isn't much time for it to get old. No during the day, like from 2 pm to 4 pm, there may be a period of 30 minutes without a customer at some Arby's restaurants. So what does the Arby's do with the chicken fingers, what do they do with the fish patties, etc? Some will keep them under hot lights, some will toss them and cook it fresh when customers finally come in.
Moral: if you don't like one Arby's, find another one and the same item may taste much better there.