Pros
Large programmes and the size of the firm means there can be lot's of diverse work on offer. If you like to work away from home and travel to the far flung parts of the UK, week after week, then Accenture might be for you.
Cons
A recognition structure that's biased against technical contributions. There are VERY few, if any, technical people in senior positions. At some point you will need to contribute sales and win work to be promoted. Non-technical people managing technical staff does not work. They inevitably vent their frustrations on the team whose careers suffer in turn. You wil not like everyone you work with. It can be very cliquey with those groups only ever promoting from within. And some people will do whatever it takes to get ahead of you.