Pros
KPMG is great place to start off as you will learn an imense amount of information about how different companies and various industries operate. If you are able to stick it out to Senior, you will have less difficulty finding a job in the private sector as opposed to others who didn't start in public accounting. The salary is competitive with other big 4 accounting firms; that being said it isn't great. You will also find that your co-workers are great people to work with, and will most likely build lasting friendships with a few of them. The in house training oppurtunities are also a great to better your technical skills.
Cons
During Busy Season (end of November through end of March) there is practically no work life balance. Most of the engagement teams will expect you to work 12-15 hour days 6-7 days a week. As the company does not pay overtime, your salary value from an hourly perspective is horrible. In addition, a number of the managers and senior managers tend to point fingers on anything and everything that doesn't work out 100% according to plan or budget. This being the case; it is the senior associate on the job who most likely will be the one who will take the blame for all of the of the short comings on the engagement. Being thrown under the bus is normal occurance in the day to day life at KPMG. Not all managers throw under the bus, but it is a good idea to quickly learn which ones do, and run for the hills if you ever get staffed on their engagements. If you are starting with the firm, it is a good idea to stick it out to the senior level. If you re-assess and feel like it is not the place for you, don't be scared to leave. The company will try to brain wash you to think that there is no better place to live, but truth be told, 99% of the people who left are happy with their decision.