Pros
I worked at Brightworks for a number of years as it went through various transitions. The main constants were: a strong and smart leader and a fun, friendly, kind and engaged group of people. Given that Brightworks is a small- to mid-sized agency, it's a place where, if you apply yourself, you can learn and grow and make contributions outside the constraints of your role. Culture fit is super important there but there are lots of places you can research what the team is like (Instagram, FB, etc).
Cons
The challenges at Brightworks are really the challenges of any agency -- sometimes tight budgets or difficult timelines. Though I've heard much worse from peers at larger agencies.