Pros
Great staff, decent pay, as many hours as you can handle. The staff I work with are great, including the managers, though obviously this could vary tremendously between stores and regions. I'm never really bored at work. Angry, tired, happy... Sure, but never bored.
Cons
The rota can be an nightmare. Your shifts can vary so wildly from week to week that your sleep and social life will most definitely suffer. If you're a particularly social person and enjoy regular weekends out and being with friends you should forget about the job right now because I haven't had a weekend off in months. One morning you're up at 3am, the next you're not on until 2pm and so on... Basically it's very hard to have any kind of regularity in your free time because the rotas are so varied and inconsistent. There's also a lot of variation in the way staff are treated. The gents are expected to do more heavy lifting, more physical work and that's fine, sure, but they're also typically the last people to get the time off that they want. In my store it's all too easy for a girl to bat her eyelids and get whatever time off she likes. Likewise certain members of staff seem to get away with murder. They perpetually under perform (making more work for the rest) without any repercussions. There really isn't that much room for advancement. At best, after many years of thankless grafting you can make your way to store manager. The money at that level is good, yes, but in return you basically have to live in the store. If you've any ambition to make it into upper management you need to reconsider because there is no opportunity for store employees to advance to that level. They would rather employ people straight out of university. My last little gripe is the uniform. The clothes are fine and good but men have to be clean shaven. This might not bother you at all but to me seems antiquated and discriminatory at best. There's no hygiene basis for it whatsoever. You are allowed facial hair for religious reasons though, which is almost more insulting. Beards are okay, basically, as long as you're the right race and skin colour.