Avantages
Very accommodating: I had a part time (16h/week) contract, but was offered shift cover to make up more hours. I also worked with a woman who could only do part time and she was not pressured to do more. Keeps you busy running around, and free coffee/tea even food sometimes in the break room. Other colleagues made sure you got our breaks. Were accommodating with holidays.
Inconvénients
A bit hectic - sometimes got called to cover shifts with a few hour's notice (though I was welcome to refuse). The work schedule changed each week and wasn't always up to date so I didn't know when I was working unless I found a supervisor to ask. Understaffing was an issue when a trainee manager came in. Left us understaffed at the end of the day or with trainee staff doing supervisor roles.