Pros
The people who work here - management and principle developers excluded - are great! Everyone is friendly and gets along well.
Cons
Management is horrible. The company is run like a family business. The CEO walks around the small office space talking very loudly on his cell phone, and a lot of these calls aren't even business related, such as calls to his family. Very unprofessional. It is very frustrating and very difficult to work in the loud environment. Also, if you are a developer, be prepared to use outdated technology - I'm talking working on projects involving SP 2007! Most of the code is unmanageable and extremely disorganized. Greystone also values billable hours, so you are "encouraged" to have as many billable hours as possible. If you are okay with making some sketchy ethical choices to make greystone money, then more power to you. Greystone managers push for code that gets the job done - so "patches" and bad conventions are okay. If you are considering working here, I would highly advise looking elsewhere. Management is oblivious to the problems of the company. It, overall, is just a dreary place to work.