Pros
If you want to become or stay overweight, the free sugared cereal and soda is great.
If you can't unwind at the end of the day without a drink or two, beer on tap is awesome.
If you get a headache from all the noise, there is a well-stocked medicine cabinet.
If you miss the chaotic, cramped quarters of your college dorm, you are in luck. Space is at a premium and everyone is allowed to decorate pretty much everywhere however they like.
If you think company meetings in conference rooms are dull, the Nerdery has a fancy tiered auditorium. And to add extra less-dull-ness there are no chairs, only bean bags!
If you are worried about skin cancer, no worries here. Almost no one sits near a window because the "office" is in a giant suburban warehouse space.
If you are male and need to get some exercise, you will probably get it looking for an open spot in a restroom.
If you think life should be more like a video game, you're in luck... the main campus has two offices separated by a train tracks (and in the winter: giant snow banks). Frogger had it way too easy.
If you are looking for career advancement and you're related to someone or have worked there since the company was under 100 employees, you'll have no trouble moving up.
If you're a software developer who thinks developers are the best people to write test plans for QA, sign up now!
If you're a software developer who prefers to get vague requirements in full before starting to write code, you will love being able to work from developer-written "scope" documents.
If you think the marketing department's biggest wins should be in branding the company in the minds of the company's own employees, you will love the hooded sweatshirts, the cool notebooks, the coffee cups with the company logo, the morale booster posters around the office, etc.
If you think industry-leading products and technology for managing your business are a waste of money and prefer home-grown, don't worry, the Nerdery has its own CRM, its own time and work management system... all based on a database system that was very innovative back in the 80s.
Cons
The Nerdery is an addiction. You will make excuses to stay here, long after it's clear you should leave.
1. You won't want to leave all your awesome coworkers, most of whom are genuinely talented, bright, and fun to work with. If you are into science fiction or video games or Dungeons and Dragons, the high concentration of others who share your passion is going to make it feel like coming home every time you walk in the door.
2. If you even remotely like dogs and puppies, you will have a hard time imagining a workplace without canine companions again.
3. The company's "core values" statement make the 10 Commandments seem like a bad first draft. Same goes for the mission statement "Be the best place in the world for nerds to work". Also, being called a "co-president" is much more likely to make you feel pride than simply being a "team member".
4. The company management are not power hungry type A jerks. They actively encourage feedback and discussion on an in-house web forum. Their door is always open to people who want/need to talk.
You will love it to death even as it drives you crazy.