Pros
Waitrose was my first job and I was there for 12 years in mainly a part time capacity whilst I studied and worked other various jobs. I found in my time there that you get out what you put in and if you work hard you get the respect of your colleagues and management. The benefits such as the yearly bonus and discount card are great and come in handy. Also free entry to English heritage sites when you show your discount card and various other things. The company is very much pro employee and the management will try and accommodate you as best it can if you have any problems.
Cons
Can be quite cliquey and dining room banter can be mighty droll if your not into dishing the dirt on your co workers but that can be found in most jobs at this level I think. Graduate trainees often come in without a clue as to how a supermarket works and are unwilling to learn, this can be frustrating for long standing staff who could do their job standing on their heads.