Pros
As someone who worked internally, not as a consultant, the one good thing I found about Perficient was the flexibility. For the majority of positions you could work from home - even when you had a local office. However, they are doing away with a lot of that. If you land in a good business unit you may work with some really great people, as I did. The business units are all different from each other because they were mainly created by acquiring small companies which are able maintain their pre-Perficient cultures for a period of time. This company structure explains why you see some great reviews and some horrid ones.
Cons
As you can read in many of the reviews, an employee is considered valuable if they are billable. So, internal employees (HR, recruiting, etc) are dispensable. The flexibility mentioned above, which was one of the greatest perks, is being taken away and they are laying employees off and then rehiring people in St. Louis (company headquarters). They also like to lay people off for bogus reasons, quite often it's poor company performance, and then within a couple months they rehire for that same position. And after laying someone off they turn around and tell management that it was the employee's poor performance that was the cause for dismissal. Upper management also asks HR employees to talk to consultants and ask them to write good reviews for this website in exchange for a gift card. I believe a large number of these one and two line decent reviews are from one of these PR pushes. Perficient loves to remind their employees of the company's values, ethics and integrity. There's a reason they have to talk about it so much...