Pros
Pay is average. Not over the minimum London living wage, but it is usually a few pennies over other retail companies. If you are lucky enough to never been sick, and know how to kiss people's butts, you could become manager within a year.
Cons
No human relationship with anyone higher than you. Management thinks they're better than anyone else. They don't take any advice from staff who has actually been working on the floor more than them. More than a few times I have seen them make horrible decision just for the sake of it. If you're sick more than two times in six months, they go through a whole process of assessing you, treating you like garbage and interrogating you like you committed a felony. They ask you questions with attitude. It drives a lot of people coming in even with high fever, just to avoid this process. Which makes them feel worse and risks to infect other people.