Vantaggi
Big companies have specialists to do every type of job function, so good for specialists who don't like to do multiple things, although not a good place for technology generalists for the same reason.
Svantaggi
In my opinion: People are not developed via their archaic stack ranking/quota system. Promotions gained thru popularity and politics and not through skills development. Most executives (SVPs and up) don't get their hands dirty at the customer/project level, yet have all the answers on non-stop internal conference calls. Old boy Accenture / Microsoft nepotism at executive leadership level. If you worked for Microsoft or Accenture 20 years ago and have a relationship, you are qualified to be a CVP or higher at Avanade. Most projects are run by Accenture hard as*es (kindly labeled 'drivers'). These folks will expect you to work all hours due to over-promising, or just because they have nothing better to do but to go back to the hotel. At best you are treated like a sub-contractor and lack a seat at the table. Accenture takes all of the leadership roles on projects, leaving Avanade the individual contributor roles which can limit your growth.