When I was a teenager I worked at McDonald's and Wendy's.... at the same time. It was a real learning experience. I greatly preferred McDonald's, to tell the truth, because it was a much better work environment. The Wendy's management was pretty terrible. When they scheduled me to work on a particular day that I couldn't, they told me I had to find a replacement. When no one on the call list would swap, they said I could either show up on the given day or get fired. It's the only time in my life I actually got fired, and I didn't mind at all. I remember the manager telling me that this would "teach me a lesson" about the "real world." Joke was on him, McD's was paying me a lot more, and so all he did was make it easier for me to take more shifts there.
I could say a lot else, but I think these training videos will give you the picture of what it's like being a Wendy's employee. They actually made us watch this crap.
McDonald's fact: the number one customer complaint about the french fries: "Not Salty Enough."