Long hours - Depending on the project or manager your life could be horrible. Often there are excuses given as to why the particular project you're on is "abnormally" intense, but if you talk to enough employees you will find that almost all of them have had one or multiple horrible projects, it is not a particularly rare occurrence. To clarify on hours, 50 hours a week is basically the minimum, with average hours being around 60 and many people up past 70... this is excluding travel time too. Horrible projects could mean you're up till 2am most weekdays, then up at 7am the next morning. While weekend work is typically not the norm, you are pretty much expected to be available on any weekend if required, or answer basic emails, which can be a pain.
Great people, except you barely get to know them - your home office may be full of people you like, but you only see them 1 day a week. Similarly, if you move to another project every few months you don't see your old teammates anymore. Great to meet people, but not great to know people.
Demanding travel schedule - Virtually every project won't be local and you'll be flying out every Monday morning and coming back every Thursday night. If you're in New York or Chicago maybe you could get 1 in 3 or 4 projects local but they may not be the most thrilling assignments. Geography is not considered enough when staffing, so sometimes you will have people in the same role flying back and forth inbetween two cities, whereas both could be local if they traded projects.
