Pros
It is a very strong company, they will always have work, it would take a LOT of screw ups to get fired. The benefits are close to unbeatable and if you stick around for 10+ years the money will be great.
Cons
You can expect to work a minimum of 50 hours a week, often up to 70+ hours a week depending on the phase of work. You will be micromanaged constantly to ensure you fit the "HP mold". Your day will start at a 6am meeting (6:30 at latest) but its very common for people to show up as early 4am to try to tackle the work load. At this meeting you will be expected to provide an hour by hour schedule of what you will be doing for the day. Expect that to be criticized by the other workers in the room. Do not expect to leave before 5pm, and expect to leave around 7pm normally. Mandatory 5pm sign ins are common, particularly on holiday weekends where people plan to hit the road early to beat traffic. It is very much a white male driven company. That being said, women and minorities are hired often, as numbers, and promoted through the lower ranks quickly to promote diversity, but rarely make it past the position of project engineer. As with most large construction companies, expect to move, often. Unlike most large construction companies, expect to move, at a moments notice, your family situation will not be considered, less than two weeks notice to move to projects across the country is the norm.