Pros
Smart people and mostly kind colleagues. One great benefit is the 401K. Since it's an employee owned company (not publicly listed) you can select to put your retirement in the company stock - which goes up every year a considerable amount. So if you're looking to park at a fairly successful institution and build your nest egg for a few years, it's a great place. Salaries are on par with other similar consultancies, maybe even higher. Lots of great folks but they are scattered all across the country. There's a good sense of autonomy in general (no one looking over your shoulders) but the shadow side of that is the isolation (See below for cons)
Cons
Somewhat impersonal work environment, similar to a lot of large consulting companies. Staff come and go with little fanfare. Half the people who were there when I started are now gone and I wasn't even aware. A somewhat disconnected, isolating, and dry office culture despite their best efforts. Very sweet people who work the front desks, and they do their best, but it's the culture. I thought maybe it was just the Washington offices that were this way, but colleagues in other cities have told me it's the same where they are. No separate pool for sick days -- everything is pulled from your PTO. So God forbid you take a vacation and then get a serious illness in the same year - you are screwed and have to "borrow" PTO from colleagues. I find it outrageous and a regressive policy that encourages people to work when they are sick. I also don't understand why, if it is an employee owned company why we have this regressive policy and can't change it. Holidays are limited to the bare minimum. While they make a big deal about honoring Veterans Day, we don't even get that day off. There's an enormous focus on (or should I say, obsession with) billing hours (aka "utilization"). If you don't bill the heck out of your clients you get warnings. Very conservative, risk averse corporate culture -- don't try to be too innovative or go against the grain - you'll get shot down quickly. Health benefits could be much better - since HQ is in red state Nebraska, they don't get fancy with acupuncture or other services that actually work for chronic issues. The dental insurance also is annoying - I was denied coverage for fluoride as well as polish on the same day as scaling. My dentist was quite shocked at this as well! I don't really recommend HDR for anyone who is not an architect or engineer - it's not an ideal environment.