Avantages
Good working environment, very supportive, loads of extra learning materials. It's a relaxed atmosphere, which is perfect ground for productivity. In my experience, I haven't had to work unpaid overtime, or do late evening releases, as I hear my friends tell me, so that's good. Personal time is respected - nobody is expected to answer calls or emails after they clock out, in fact people are encouraged to 'disconnect'. The work envirnonment is fantastic and work/life balance is good, however my dissapointment lies in the career progression opportunities and boring work. If this is important to you, then I'd recommend Capgemini. If progressing professionally and not being a pencil-pusher is more important, read on.
Inconvénients
Most of the projects are public sector, so it's highly likely you'll be assigned to a government project. In my experience, they're slow and full of paperwork, and jumping through unnecessary hoops that seem rather counterproductive. I'm stuck doing, what feels like, meaningless work a lot of the time. First adding something, the removing it - not really value generating if you ask me. We were told that this year only 6% of applicants will get a promotion (and for engineering its even less!). This is very demotivating, especially after putting my heart and soul into the project. It's not uncommon for big companies to hire externally when a position opens up - it makes sense to have 8 people fighting for a senior position, and then tell them 'ooh tough luck, try hard and maybe in the next promotion cycle you will get it'. That way you get 9 people performing senior responsibility, for the price of 1 senior and 8 mids.