Avantages
Management is great. They really strive to ensure that their employees are happy. They even will pay for up to two trips a year for you to get back home in an emergency during the middle of the week at a client.
You only travel Mon-Thurs unless the client states otherwise. CSS tries really hard for you to be able to get home on Thursdays so that you can be with your family.
Inconvénients
Traveling each and every week takes a toll. It isn't for everyone but a lot of my co-workers didn't mind it and in fact loved it. Some clients can be a real pain (i.e. even though they are paying a ton of money for your expertise, they are unwilling to listen to your advice)