Pros
I met some really great people and learned a few new skills. The bathrooms were always clean. There really weren't any perks.
Cons
Everything else. The owners have the most ridiculous rules and expectations, e.g., no newspapers in the building, no parking with your exhaust pipe next to a grassy area, no using the elevators unless moving equipment. Strict business dress code. Furthermore, they let a large dog freely roam the building, in case anyone might be allergic or have an aversion to large dogs. The only goal is to line the pockets of the owners. The general attitude is that they hate the idea of even having employees; paying them is even worse. And the pay is not even remotely competitive. I have seen the same job listings on craigslist stay open for well over a year, for seemingly entry-level work.