Sainsbury's can and will teach you a lot during your career, There will be times when pressure will be high and days will be hard but you will come out a strong leader. work life balance for me was becoming an issue only because I have children that do not live with me therefore weekends are what I need back to see them.
other than that hours are not terrible just shifts will always change so you must be a person that can move with the company and be willing to change if needed.
holiday pay, sick pay, start up pension, salary pay
constant changing shifts, minimal weekends, over hour to travel