Pros
Free staff meals are always a bonus! Plus discounts when you're not at work. Fast paced, busy, vibrant environment so gets you good working experience for future and teaches you lots of different skills. Store works round your availability with hours and it's easy to get a shift covered which means it's particularly good for students and young mothers who have a weird working schedule. Easy to work your way up to apprenticeships, team leadership etc.
Cons
Management is poor. You get good managers but also bad ones and there's little that's done to change that. I often find some managers let other team members get away with laziness while the hard workers pick up the slack. Although you get good customers you do get a lot of awful ones who think because you work at KFC they can treat you awfully over chicken. Working late and doing jobs like cleaning toilets isn't fun. The pay is minimum meaning £4 for under 18s, 5.60 for 18-21 and national minimum wage for those 21 and over which is appalling but expected.